SEC Info - ViacomCBS Inc. - ‘10-K’ for 12/31/19

SEC Info℠

Home

Help

Please Sign In

ViacomCBS Inc. – ‘10-K’ for 12/31/19 – ‘EX-101.DEF’

On: Thursday, 2/20/20, at 5:33pm ET · For: 12/31/19 · Accession #: 813828-20-13 · File #: 1-09553

  As Of               Filer                 Filing    For·On·As Docs:Size

 2/20/20  ViacomCBS Inc.                    10-K       12/31/19  158:33M

Annual Report — Form 10-K — Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML   3.70M 
 2: EX-4.A      Instrument Defining the Rights of Security Holders  HTML     51K 
 3: EX-10.BB    Material Contract                                   HTML    169K 
 4: EX-10.CC    Material Contract                                   HTML     49K 
 5: EX-10.GG    Material Contract                                   HTML    187K 
 6: EX-10.HH    Material Contract                                   HTML     58K 
 7: EX-10.JJ    Material Contract                                   HTML    140K 
 8: EX-21       Subsidiaries List                                   HTML    233K 
 9: EX-23.A     Consent of Experts or Counsel                       HTML     43K 
10: EX-24       Power of Attorney                                   HTML     83K 
11: EX-31.A     Certification -- §302 - SOA'02                      HTML     48K 
12: EX-31.B     Certification -- §302 - SOA'02                      HTML     48K 
13: EX-32.A     Certification -- §906 - SOA'02                      HTML     42K 
14: EX-32.B     Certification -- §906 - SOA'02                      HTML     42K 
39: R1          Cover Page                                          HTML    107K 
116: R2          Consolidated Statements of Operations               HTML    163K  
139: R3          Consolidated Statements of Comprehensive Income     HTML     73K  
88: R4          Consolidated Balance Sheets                         HTML    163K 
40: R5          Consolidated Balance Sheets (Parenthetical)         HTML     55K 
117: R6          Consolidated Statements of Cash Flows               HTML    160K  
141: R7          Consolidated Statements of Cash Flows               HTML     49K  
                (Parenthetical)                                                  
91: R8          Consolidated Statements of Stockholders' Equity     HTML    105K 
38: R9          Basis of Presentation and Summary of Significant    HTML    162K 
                Accounting Policies                                              
80: R10         Property and Equipment                              HTML     64K 
29: R11         Programming and Other Inventory                     HTML     62K 
108: R12         Goodwill and Other Intangible Assets                HTML    282K  
129: R13         Restructuring, Programming Charges and Other        HTML    249K  
                Corporate Matters                                                
77: R14         Related Parties                                     HTML     60K 
26: R15         Acquisition and Investments                         HTML     85K 
105: R16         Debt                                                HTML    133K  
126: R17         Leases                                              HTML    297K  
81: R18         Financial Instruments                               HTML     56K 
25: R19         Fair Value Measurements                             HTML     96K 
104: R20         Stockholders' Equity                                HTML    141K  
157: R21         Stock-Based Compensation                            HTML    133K  
70: R22         Income Taxes                                        HTML    164K 
53: R23         Pension and Other Postretirement Benefits           HTML    436K 
101: R24         Redeemable Noncontrolling Interest                  HTML     60K  
154: R25         Segment and Revenue Information                     HTML    232K  
67: R26         Discontinued Operations                             HTML     92K 
50: R27         Commitments and Contingencies                       HTML    108K 
100: R28         Supplemental Financial Information                  HTML     81K  
158: R29         Quarterly Financial Data (Unaudited)                HTML    190K  
131: R30         Schedule II - Valuation and Qualifying Accounts     HTML    128K  
110: R31         Basis of Presentation and Summary of Significant    HTML    181K  
                Accounting Policies (Policies)                                   
21: R32         Basis of Presentation and Summary of Significant    HTML     95K 
                Accounting Policies (Tables)                                     
72: R33         Property and Equipment (Tables)                     HTML     64K 
134: R34         Programming and Other Inventory (Tables)            HTML     84K  
113: R35         Goodwill and Other Intangible Assets (Tables)       HTML    331K  
24: R36         Restructuring, Programming Charges and Other        HTML    135K 
                Corporate Matters (Tables)                                       
75: R37         Related Parties (Tables)                            HTML     56K 
130: R38         Acquisition and Investments (Tables)                HTML     60K  
114: R39         Debt (Tables)                                       HTML    119K  
147: R40         Leases (Tables)                                     HTML    167K  
92: R41         Financial Instruments (Tables)                      HTML     50K 
48: R42         Fair Value Measurements (Tables)                    HTML     97K 
64: R43         Stockholders' Equity (Tables)                       HTML    128K 
148: R44         Stock-Based Compensation (Tables)                   HTML    129K  
93: R45         Income Taxes (Tables)                               HTML    161K 
49: R46         Pension and Other Postretirement Benefits (Tables)  HTML    443K 
65: R47         Redeemable Noncontrolling Interest (Tables)         HTML     58K 
146: R48         Segment and Revenue Information (Tables)            HTML    264K  
94: R49         Discontinued Operations (Tables)                    HTML     96K 
119: R50         Commitments and Contingencies (Tables)              HTML     77K  
137: R51         Supplemental Financial Information (Tables)         HTML     82K  
90: R52         Quarterly Financial Data (Unaudited) (Tables)       HTML    190K 
37: R53         Basis of Presentation and Summary of Significant    HTML    126K 
                Accounting Policies (Narrative) (Details)                        
118: R54         Basis of Presentation and Summary of Significant    HTML     50K  
                Accounting Policies (Change in Reporting Entity)                 
                (Details)                                                        
136: R55         Basis of Presentation and Summary of Significant    HTML     55K  
                Accounting Policies (Property and Equipment)                     
                (Details)                                                        
89: R56         Basis of Presentation and Summary of Significant    HTML     59K 
                Accounting Policies (Unrecognized Revenues Under                 
                Contract) (Details)                                              
36: R57         Basis of Presentation and Summary of Significant    HTML     53K 
                Accounting Policies (Net Earnings (Loss) per                     
                Common Share) (Details)                                          
115: R58         Basis of Presentation and Summary of Significant    HTML     43K  
                Accounting Policies (Recently Adopted Accounting                 
                Pronouncements Narrative) (Details)                              
138: R59         Property and Equipment (Details)                    HTML     83K  
60: R60         Programming and Other Inventory (Details)           HTML     82K 
45: R61         Goodwill and Other Intangible Assets (Narrative)    HTML     58K 
                (Details)                                                        
97: R62         Goodwill and Other Intangible Assets (Goodwill)     HTML     86K 
                (Details)                                                        
151: R63         Goodwill and Other Intangible Assets (Intangible    HTML     73K  
                Assets) (Details)                                                
59: R64         Goodwill and Other Intangible Assets (Amortization  HTML     44K 
                Expense) (Details)                                               
44: R65         Goodwill and Other Intangible Assets (Future        HTML     53K 
                Amortization Expense) (Details)                                  
96: R66         Restructuring, Programming Charges and Other        HTML     68K 
                Corporate Matters (Restructuring and Other                       
                Corporate Matters) (Details)                                     
150: R67         Restructuring, Programming Charges and Other        HTML     65K  
                Corporate Matters (Narrative) (Details)                          
62: R68         Restructuring, Programming Charges and Other        HTML     81K 
                Corporate Matters (Rollforward) (Details)                        
41: R69         Related Parties (Narrative) (Details)               HTML     55K 
31: R70         Related Parties (Schedule of Related Party          HTML     58K 
                Transactions) (Details)                                          
85: R71         Acquisition and Investments (Acquisitions           HTML     84K 
                Narrative) (Details)                                             
143: R72         Acquisition and Investments (Acquisition Purchase   HTML     71K  
                Price Allocation) (Details)                                      
121: R73         Acquisition and Investments (Investments            HTML     99K  
                Narrative) (Details)                                             
32: R74         Acquisition and Investments (Variable Interest      HTML     56K 
                Entities Narrative) (Details)                                    
86: R75         Debt (Schedule of Debt) (Details)                   HTML    174K 
144: R76         Debt (Narrative) (Details)                          HTML     94K  
122: R77         Debt (Maturities of Long-Term Debt) (Details)       HTML     58K  
35: R78         Debt (Commercial Paper Narrative) (Details)         HTML     55K 
83: R79         Debt (Credit Facility Narrative) (Details)          HTML     64K 
30: R80         Leases (Balance Sheet Amounts) (Details)            HTML     59K 
84: R81         Leases (Weighted Average) (Details)                 HTML     52K 
142: R82         Leases (Lease Cost) (Details)                       HTML     59K  
120: R83         Leases (Operating and Financing Cash Flows)         HTML     48K  
                (Details)                                                        
33: R84         Leases (Future Minimum Payments) (Details)          HTML     81K 
87: R85         Leases (Future Minimum Payments Prior to Adoption)  HTML     84K 
                (Details)                                                        
145: R86         Leases (Narrative) (Details)                        HTML     61K  
123: R87         Leases (Future Lease Income as Lessor) (Details)    HTML     56K  
34: R88         Financial Instruments (Details)                     HTML     65K 
82: R89         Fair Value Measurements (Details)                   HTML     67K 
61: R90         Stockholders' Equity (Narrative) (Details)          HTML     85K 
46: R91         Stockholders' Equity (Accumulated Other             HTML     88K 
                Comprehensive Income) (Details)                                  
98: R92         Stock-Based Compensation (Expense) (Details)        HTML     71K 
152: R93         Stock-Based Compensation (RSUs and PSUs) (Details)  HTML     91K  
58: R94         Stock-Based Compensation (Stock Options,            HTML     80K 
                Narrative) (Details)                                             
43: R95         Stock-Based Compensation (Stock Options,            HTML     57K 
                Black-Scholes Assumptions) (Details)                             
95: R96         Stock-Based Compensation (Stock-Options,            HTML     70K 
                Rollforward) (Details)                                           
149: R97         Stock-Based Compensation (Stock Options, Other      HTML     49K  
                Information) (Details)                                           
63: R98         Income Taxes (Income (Loss) from Continuing         HTML     48K 
                Operations) (Details)                                            
42: R99         Income Taxes (Provision for Income Taxes)           HTML     72K 
                (Details)                                                        
23: R100        Income Taxes (Narrative) (Details)                  HTML     92K 
74: R101        Income Taxes (Effective Income Tax Rate             HTML     85K 
                Reconciliation) (Details)                                        
133: R102        Income Taxes (Deferred Income Tax Assets and        HTML     88K  
                Liabilities) (Details)                                           
112: R103        Income Taxes (Unrecognized Tax Benefits) (Details)  HTML     57K  
22: R104        Pension and Other Postretirement Benefits (Change   HTML     87K 
                in Benefit Obligation) (Details)                                 
73: R105        Pension and Other Postretirement Benefits (Change   HTML     65K 
                In Plan Assets) (Details)                                        
132: R106        Pension and Other Postretirement Benefits (Funded   HTML     69K  
                Status of Pension and Postretirement Benefit                     
                Obligations) (Details)                                           
111: R107        Pension and Other Postretirement Benefits (Funded   HTML     65K  
                Status and Amounts Recognized in Accumulated Other               
                Comprehensive Income (Loss) on the Consolidated                  
                Balance Sheets) (Details)                                        
20: R108        Pension and Other Postretirement Benefits           HTML     50K 
                (Accumulated Benefit Obligation in Excess of Plan                
                Assets) (Details)                                                
76: R109        Pension and Other Postretirement Benefits           HTML    112K 
                (Components of Net Periodic Benefit Cost and                     
                Amounts Recognized in Other Comprehensive Income                 
                (Loss) (Details)                                                 
68: R110        Pension and Other Postretirement Benefits           HTML     77K 
                (Assumptions) (Details)                                          
51: R111        Pension and Other Postretirement Benefits           HTML     52K 
                (Sensitivity) (Details)                                          
102: R112        Pension and Other Postretirement Benefits (Plan     HTML     68K  
                Asset Allocations) (Details)                                     
155: R113        Pension and Other Postretirement Benefits (Fair     HTML    113K  
                Value Measurements) (Details)                                    
69: R114        Pension and Other Postretirement Benefits (Future   HTML     82K 
                Benefit Payments) (Details)                                      
52: R115        Pension and Other Postretirement Benefits           HTML     81K 
                (Multiemployer Pension and Postretirement Benefit                
                Plans) (Details)                                                 
103: R116        Pension and Other Postretirement Benefits (Defined  HTML     43K  
                Contribution Plans) (Details)                                    
156: R117        Redeemable Noncontrolling Interest (Details)        HTML     54K  
66: R118        Segment and Revenue Information (Revenues)          HTML    113K 
                (Details)                                                        
56: R119        Segment and Revenue Information (Operating Income   HTML    140K 
                (Loss)) (Details)                                                
106: R120        Segment and Revenue Information (Depreciation and   HTML     56K  
                Amortization) (Details)                                          
127: R121        Segment and Revenue Information (Capital            HTML     56K  
                Expenditures) (Details)                                          
78: R122        Segment and Revenue Information (Assets) (Details)  HTML     62K 
27: R123        Segment and Revenue Information (Revenue by Type)   HTML     70K 
                (Details)                                                        
107: R124        Segment and Revenue Information (Long-lived         HTML     47K  
                Assets) (Details)                                                
128: R125        Discontinued Operations (Narrative) (Details)       HTML     50K  
79: R126        Discontinued Operations (Net Earnings (Loss))       HTML    116K 
                (Details)                                                        
28: R127        Commitments and Contingencies (Narrative)           HTML     62K 
                (Details)                                                        
109: R128        Commitments and Contingencies (Commitments)         HTML     93K  
                (Details)                                                        
125: R129        Commitments and Contingencies (Legal Matters        HTML     59K  
                Narrative) (Details)                                             
153: R130        Supplemental Financial Information (Components of   HTML     55K  
                Other Items, Net) (Details)                                      
99: R131        Supplemental Financial Information (Supplemental    HTML     59K 
                Cash Flow Information) (Details)                                 
57: R132        Quarterly Financial Data (Unaudited) (Details)      HTML    118K 
71: R133        Schedule II - Valuation and Qualifying Accounts     HTML     60K 
                (Details)                                                        
55: R9999       Uncategorized Items - a2019k.htm                    HTML     41K 
140: XML         IDEA XML File -- Filing Summary                      XML    310K  
54: XML         XBRL Instance -- a2019k_htm                          XML   7.69M 
47: EXCEL       IDEA Workbook of Financial Reports                  XLSX    193K 
16: EX-101.CAL  XBRL Calculations -- viac-20191231_cal               XML    543K 
17: EX-101.DEF  XBRL Definitions -- viac-20191231_def                XML   1.74M 
18: EX-101.LAB  XBRL Labels -- viac-20191231_lab                     XML   3.68M 
19: EX-101.PRE  XBRL Presentations -- viac-20191231_pre              XML   2.37M 
15: EX-101.SCH  XBRL Schema -- viac-20191231                         XSD    343K 
124: JSON        XBRL Instance as JSON Data -- MetaLinks              768±  1.17M  
135: ZIP         XBRL Zipped Folder -- 0000813828-20-000013-xbrl      Zip   2.34M

‘EX-101.DEF’ — XBRL Definitions — viac-20191231_def

This Exhibit is an XBRL XML File.

<?xml version="1.0" encoding="windows-1252"?>

<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestments" xlink:href="viac-20191231.xsd#AcquisitionAndInvestments" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestmentsAcquisitionPurchasePriceAllocationDetails" xlink:href="viac-20191231.xsd#AcquisitionAndInvestmentsAcquisitionPurchasePriceAllocationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestmentsAcquisitionsNarrativeDetails" xlink:href="viac-20191231.xsd#AcquisitionAndInvestmentsAcquisitionsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestmentsInvestmentsNarrativeDetails" xlink:href="viac-20191231.xsd#AcquisitionAndInvestmentsInvestmentsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestmentsTables" xlink:href="viac-20191231.xsd#AcquisitionAndInvestmentsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/AcquisitionAndInvestmentsVariableInterestEntitiesNarrativeDetails" xlink:href="viac-20191231.xsd#AcquisitionAndInvestmentsVariableInterestEntitiesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPolicies" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPolicies" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesChangeInReportingEntityDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesChangeInReportingEntityDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNarrativeDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNetEarningsLossPerCommonShareDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNetEarningsLossPerCommonShareDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsNarrativeDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesUnrecognizedRevenuesUnderContractDetails" xlink:href="viac-20191231.xsd#BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesUnrecognizedRevenuesUnderContractDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CommitmentsAndContingencies" xlink:href="viac-20191231.xsd#CommitmentsAndContingencies" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CommitmentsAndContingenciesCommitmentsDetails" xlink:href="viac-20191231.xsd#CommitmentsAndContingenciesCommitmentsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CommitmentsAndContingenciesLegalMattersNarrativeDetails" xlink:href="viac-20191231.xsd#CommitmentsAndContingenciesLegalMattersNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CommitmentsAndContingenciesNarrativeDetails" xlink:href="viac-20191231.xsd#CommitmentsAndContingenciesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CommitmentsAndContingenciesTables" xlink:href="viac-20191231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedBalanceSheets" xlink:href="viac-20191231.xsd#ConsolidatedBalanceSheets" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="viac-20191231.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="viac-20191231.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedStatementsOfCashFlowsParenthetical" xlink:href="viac-20191231.xsd#ConsolidatedStatementsOfCashFlowsParenthetical" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="viac-20191231.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedStatementsOfOperations" xlink:href="viac-20191231.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="viac-20191231.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/CoverPage" xlink:href="viac-20191231.xsd#CoverPage" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/Debt" xlink:href="viac-20191231.xsd#Debt" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtCommercialPaperNarrativeDetails" xlink:href="viac-20191231.xsd#DebtCommercialPaperNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtCreditFacilityNarrativeDetails" xlink:href="viac-20191231.xsd#DebtCreditFacilityNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtMaturitiesOfLongTermDebtDetails" xlink:href="viac-20191231.xsd#DebtMaturitiesOfLongTermDebtDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtNarrativeDetails" xlink:href="viac-20191231.xsd#DebtNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtScheduleOfDebtDetails" xlink:href="viac-20191231.xsd#DebtScheduleOfDebtDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DebtTables" xlink:href="viac-20191231.xsd#DebtTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DiscontinuedOperations" xlink:href="viac-20191231.xsd#DiscontinuedOperations" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DiscontinuedOperationsNarrativeDetails" xlink:href="viac-20191231.xsd#DiscontinuedOperationsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DiscontinuedOperationsNetEarningsLossDetails" xlink:href="viac-20191231.xsd#DiscontinuedOperationsNetEarningsLossDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/DiscontinuedOperationsTables" xlink:href="viac-20191231.xsd#DiscontinuedOperationsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FairValueMeasurements" xlink:href="viac-20191231.xsd#FairValueMeasurements" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FairValueMeasurementsDetails" xlink:href="viac-20191231.xsd#FairValueMeasurementsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FairValueMeasurementsTables" xlink:href="viac-20191231.xsd#FairValueMeasurementsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FinancialInstruments" xlink:href="viac-20191231.xsd#FinancialInstruments" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FinancialInstrumentsDetails" xlink:href="viac-20191231.xsd#FinancialInstrumentsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/FinancialInstrumentsTables" xlink:href="viac-20191231.xsd#FinancialInstrumentsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsAmortizationExpenseDetails" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsAmortizationExpenseDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsFutureAmortizationExpenseDetails" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsGoodwillDetails" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsGoodwillDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsIntangibleAssetsDetails" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsIntangibleAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:href="viac-20191231.xsd#GoodwillAndOtherIntangibleAssetsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxes" xlink:href="viac-20191231.xsd#IncomeTaxes" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesDeferredIncomeTaxAssetsAndLiabilitiesDetails" xlink:href="viac-20191231.xsd#IncomeTaxesDeferredIncomeTaxAssetsAndLiabilitiesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesEffectiveIncomeTaxRateReconciliationDetails" xlink:href="viac-20191231.xsd#IncomeTaxesEffectiveIncomeTaxRateReconciliationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesIncomeLossFromContinuingOperationsDetails" xlink:href="viac-20191231.xsd#IncomeTaxesIncomeLossFromContinuingOperationsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesNarrativeDetails" xlink:href="viac-20191231.xsd#IncomeTaxesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesProvisionForIncomeTaxesDetails" xlink:href="viac-20191231.xsd#IncomeTaxesProvisionForIncomeTaxesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesTables" xlink:href="viac-20191231.xsd#IncomeTaxesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:href="viac-20191231.xsd#IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/Leases" xlink:href="viac-20191231.xsd#Leases" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesBalanceSheetAmountsDetails" xlink:href="viac-20191231.xsd#LeasesBalanceSheetAmountsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesFutureLeaseIncomeAsLessorDetails" xlink:href="viac-20191231.xsd#LeasesFutureLeaseIncomeAsLessorDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesFutureMinimumPaymentsDetails" xlink:href="viac-20191231.xsd#LeasesFutureMinimumPaymentsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesFutureMinimumPaymentsPriorToAdoptionDetails" xlink:href="viac-20191231.xsd#LeasesFutureMinimumPaymentsPriorToAdoptionDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesLeaseCostDetails" xlink:href="viac-20191231.xsd#LeasesLeaseCostDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesNarrativeDetails" xlink:href="viac-20191231.xsd#LeasesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesOperatingAndFinancingCashFlowsDetails" xlink:href="viac-20191231.xsd#LeasesOperatingAndFinancingCashFlowsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesTables" xlink:href="viac-20191231.xsd#LeasesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/LeasesWeightedAverageDetails" xlink:href="viac-20191231.xsd#LeasesWeightedAverageDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefits" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefits" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsAccumulatedBenefitObligationInExcessOfPlanAssetsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsAccumulatedBenefitObligationInExcessOfPlanAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsAssumptionsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsAssumptionsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsChangeInBenefitObligationDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsChangeInBenefitObligationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsChangeInPlanAssetsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsChangeInPlanAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsComponentsOfNetPeriodicBenefitCostAndAmountsRecognizedInOtherComprehensiveIncomeLossDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsComponentsOfNetPeriodicBenefitCostAndAmountsRecognizedInOtherComprehensiveIncomeLossDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsDefinedContributionPlansDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsDefinedContributionPlansDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFairValueMeasurementsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsFairValueMeasurementsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFundedStatusAndAmountsRecognizedInAccumulatedOtherComprehensiveIncomeLossOnConsolidatedBalanceSheetsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsFundedStatusAndAmountsRecognizedInAccumulatedOtherComprehensiveIncomeLossOnConsolidatedBalanceSheetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFundedStatusOfPensionAndPostretirementBenefitObligationsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsFundedStatusOfPensionAndPostretirementBenefitObligationsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFutureBenefitPaymentsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsFutureBenefitPaymentsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsMultiemployerPensionAndPostretirementBenefitPlansDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsMultiemployerPensionAndPostretirementBenefitPlansDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsPlanAssetAllocationsDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsPlanAssetAllocationsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsSensitivityDetails" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsSensitivityDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsTables" xlink:href="viac-20191231.xsd#PensionAndOtherPostretirementBenefitsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ProgrammingAndOtherInventory" xlink:href="viac-20191231.xsd#ProgrammingAndOtherInventory" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ProgrammingAndOtherInventoryDetails" xlink:href="viac-20191231.xsd#ProgrammingAndOtherInventoryDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ProgrammingAndOtherInventoryTables" xlink:href="viac-20191231.xsd#ProgrammingAndOtherInventoryTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PropertyAndEquipment" xlink:href="viac-20191231.xsd#PropertyAndEquipment" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PropertyAndEquipmentDetails" xlink:href="viac-20191231.xsd#PropertyAndEquipmentDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/PropertyAndEquipmentTables" xlink:href="viac-20191231.xsd#PropertyAndEquipmentTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/QuarterlyFinancialDataUnaudited" xlink:href="viac-20191231.xsd#QuarterlyFinancialDataUnaudited" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/QuarterlyFinancialDataUnauditedDetails" xlink:href="viac-20191231.xsd#QuarterlyFinancialDataUnauditedDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/QuarterlyFinancialDataUnauditedTables" xlink:href="viac-20191231.xsd#QuarterlyFinancialDataUnauditedTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RedeemableNoncontrollingInterest" xlink:href="viac-20191231.xsd#RedeemableNoncontrollingInterest" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RedeemableNoncontrollingInterestDetails" xlink:href="viac-20191231.xsd#RedeemableNoncontrollingInterestDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RedeemableNoncontrollingInterestTables" xlink:href="viac-20191231.xsd#RedeemableNoncontrollingInterestTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RelatedParties" xlink:href="viac-20191231.xsd#RelatedParties" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RelatedPartiesNarrativeDetails" xlink:href="viac-20191231.xsd#RelatedPartiesNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RelatedPartiesScheduleOfRelatedPartyTransactionsDetails" xlink:href="viac-20191231.xsd#RelatedPartiesScheduleOfRelatedPartyTransactionsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RelatedPartiesTables" xlink:href="viac-20191231.xsd#RelatedPartiesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMatters" xlink:href="viac-20191231.xsd#RestructuringProgrammingChargesAndOtherCorporateMatters" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersNarrativeDetails" xlink:href="viac-20191231.xsd#RestructuringProgrammingChargesAndOtherCorporateMattersNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersRestructuringAndOtherCorporateMattersDetails" xlink:href="viac-20191231.xsd#RestructuringProgrammingChargesAndOtherCorporateMattersRestructuringAndOtherCorporateMattersDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersRollforwardDetails" xlink:href="viac-20191231.xsd#RestructuringProgrammingChargesAndOtherCorporateMattersRollforwardDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersTables" xlink:href="viac-20191231.xsd#RestructuringProgrammingChargesAndOtherCorporateMattersTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:href="viac-20191231.xsd#ScheduleIiValuationAndQualifyingAccounts" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:href="viac-20191231.xsd#ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformation" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformation" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationAssetsDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationCapitalExpendituresDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationCapitalExpendituresDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationDepreciationAndAmortizationDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationDepreciationAndAmortizationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationLongLivedAssetsDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationLongLivedAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationOperatingIncomeLossDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationOperatingIncomeLossDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationRevenueByTypeDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationRevenueByTypeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationRevenuesDetails" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationRevenuesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SegmentAndRevenueInformationTables" xlink:href="viac-20191231.xsd#SegmentAndRevenueInformationTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensation" xlink:href="viac-20191231.xsd#StockBasedCompensation" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationExpenseDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationExpenseDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationRsusAndPsusDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationRsusAndPsusDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationStockOptionsBlackScholesAssumptionsDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationStockOptionsBlackScholesAssumptionsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationStockOptionsNarrativeDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationStockOptionsNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationStockOptionsOtherInformationDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationStockOptionsOtherInformationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationStockOptionsRollforwardDetails" xlink:href="viac-20191231.xsd#StockBasedCompensationStockOptionsRollforwardDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockBasedCompensationTables" xlink:href="viac-20191231.xsd#StockBasedCompensationTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockholdersEquity" xlink:href="viac-20191231.xsd#StockholdersEquity" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockholdersEquityAccumulatedOtherComprehensiveIncomeDetails" xlink:href="viac-20191231.xsd#StockholdersEquityAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockholdersEquityNarrativeDetails" xlink:href="viac-20191231.xsd#StockholdersEquityNarrativeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/StockholdersEquityTables" xlink:href="viac-20191231.xsd#StockholdersEquityTables" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SupplementalFinancialInformation" xlink:href="viac-20191231.xsd#SupplementalFinancialInformation" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SupplementalFinancialInformationComponentsOfOtherItemsNetDetails" xlink:href="viac-20191231.xsd#SupplementalFinancialInformationComponentsOfOtherItemsNetDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SupplementalFinancialInformationSupplementalCashFlowInformationDetails" xlink:href="viac-20191231.xsd#SupplementalFinancialInformationSupplementalCashFlowInformationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://www.viacbs.com/role/SupplementalFinancialInformationTables" xlink:href="viac-20191231.xsd#SupplementalFinancialInformationTables" xlink:type="simple"/>

<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple"/>

<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple"/>

<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple"/>

<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple"/>

<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestments" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestmentsAcquisitionPurchasePriceAllocationDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_934D61D3E9F8403B22D6634593496977" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_934D61D3E9F8403B22D6634593496977" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1CE41C0F34A14D695E21634593492D05" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_934D61D3E9F8403B22D6634593496977" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1CE41C0F34A14D695E21634593492D05" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1B22ABDECEE61B63BA446345934A3205_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1CE41C0F34A14D695E21634593492D05" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1B22ABDECEE61B63BA446345934A3205_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1CE41C0F34A14D695E21634593492D05" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1B22ABDECEE61B63BA446345934A3205" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PlutoTVMember" xlink:label="loc_viac_PlutoTVMember_6C42C5FBA9FF9103EE676345934A258C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1B22ABDECEE61B63BA446345934A3205" xlink:to="loc_viac_PlutoTVMember_6C42C5FBA9FF9103EE676345934A258C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_667D8025F47124B9F7D06345934B4DA7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_667D8025F47124B9F7D06345934B4DA7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_BF94BECB8B1ED32279D36345934B9AD4" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_BF94BECB8B1ED32279D36345934B9AD4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_772C5A80187C8D8A5ADD6345934B9774" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_Goodwill_772C5A80187C8D8A5ADD6345934B9774" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_D70BB0EB0DA21464FD726345934CC9AC" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_D70BB0EB0DA21464FD726345934CC9AC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_0BD2CC0A91AF1CB0D3E66345934C2EEA" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_0BD2CC0A91AF1CB0D3E66345934C2EEA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_725C21B11C1A66E78B426345934C415E" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_725C21B11C1A66E78B426345934C415E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_CA73D127D49F8A0621F76345934C273A" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_CA73D127D49F8A0621F76345934C273A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedLiabilities" xlink:label="loc_viac_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedLiabilities_F7107BD2C69DA646BFF46345934CA27F" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_viac_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedLiabilities_F7107BD2C69DA646BFF46345934CA27F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_ACCF386F3D4BFCE7436F6345934DBD77" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_ACCF386F3D4BFCE7436F6345934DBD77" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_880D051F4B012AB61BCB6345934D23DD" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_880D051F4B012AB61BCB6345934D23DD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_8E44049E99EFB3DE29256345934D0B3F" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_544E350BF20B17237D7C6345934AEE85" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_8E44049E99EFB3DE29256345934D0B3F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestmentsAcquisitionsNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B6E112A49CA93EC51D8B638CE965F7E1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B6E112A49CA93EC51D8B638CE965F7E1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_81F8DE57B2D39786A27D638CE966CE2A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B6E112A49CA93EC51D8B638CE965F7E1" xlink:to="loc_us-gaap_RelatedPartyDomain_81F8DE57B2D39786A27D638CE966CE2A_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B6E112A49CA93EC51D8B638CE965F7E1" xlink:to="loc_us-gaap_RelatedPartyDomain_81F8DE57B2D39786A27D638CE966CE2A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvesteeMember" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_4F527B3F903795CD4908638CE9664202" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_81F8DE57B2D39786A27D638CE966CE2A" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_4F527B3F903795CD4908638CE9664202" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipAxis" xlink:label="loc_srt_OwnershipAxis_6CC1D50FEF5DC38BACA2638CE9660FDE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:to="loc_srt_OwnershipAxis_6CC1D50FEF5DC38BACA2638CE9660FDE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_0F22B2BEB294E9C0C3DD638CE96630CE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_6CC1D50FEF5DC38BACA2638CE9660FDE" xlink:to="loc_srt_OwnershipDomain_0F22B2BEB294E9C0C3DD638CE96630CE_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_0F22B2BEB294E9C0C3DD638CE96630CE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_6CC1D50FEF5DC38BACA2638CE9660FDE" xlink:to="loc_srt_OwnershipDomain_0F22B2BEB294E9C0C3DD638CE96630CE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_POPMember" xlink:label="loc_viac_POPMember_3F440C1779C2C1879974638CE967D0D2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_0F22B2BEB294E9C0C3DD638CE96630CE" xlink:to="loc_viac_POPMember_3F440C1779C2C1879974638CE967D0D2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_BBB06E952021F7E9C494638CE9677189" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_BBB06E952021F7E9C494638CE9677189" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BBB06E952021F7E9C494638CE9677189" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BBB06E952021F7E9C494638CE9677189" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PlutoTVMember" xlink:label="loc_viac_PlutoTVMember_30D314E89556ECBD129E638CE96875A0" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:to="loc_viac_PlutoTVMember_30D314E89556ECBD129E638CE96875A0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_POPMember" xlink:label="loc_viac_POPMember_6EB627F34C70268544B1638CE9682C6C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:to="loc_viac_POPMember_6EB627F34C70268544B1638CE9682C6C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TenNetworksHoldingsLimitedMember" xlink:label="loc_viac_TenNetworksHoldingsLimitedMember_3A741F046D800C957990638CE968A8C1" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:to="loc_viac_TenNetworksHoldingsLimitedMember_3A741F046D800C957990638CE968A8C1" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_MiramaxMember" xlink:label="loc_viac_MiramaxMember_D4B482255BB61A6452B8638CE9682B07" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_745FB59ABBC18AFDB0FE638CE967B7D3" xlink:to="loc_viac_MiramaxMember_D4B482255BB61A6452B8638CE9682B07" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementScenarioAxis" xlink:label="loc_srt_StatementScenarioAxis_6A93E5ABDF76CF540228638CE969AF83" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A0D218468835DE25E23E638CE96571F0" xlink:to="loc_srt_StatementScenarioAxis_6A93E5ABDF76CF540228638CE969AF83" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srt_ScenarioUnspecifiedDomain_7BA6D0AAF58022E58887638CE96924DE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_6A93E5ABDF76CF540228638CE969AF83" xlink:to="loc_srt_ScenarioUnspecifiedDomain_7BA6D0AAF58022E58887638CE96924DE_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_6A93E5ABDF76CF540228638CE969AF83" xlink:to="loc_srt_ScenarioUnspecifiedDomain_7BA6D0AAF58022E58887638CE96924DE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ScenarioForecastMember" xlink:label="loc_srt_ScenarioForecastMember_5A86FC3B74EA5098F38E638CE969B9C8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_7BA6D0AAF58022E58887638CE96924DE" xlink:to="loc_srt_ScenarioForecastMember_5A86FC3B74EA5098F38E638CE969B9C8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_0F5884A8E092C1B74618638CE96F69D5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_0F5884A8E092C1B74618638CE96F69D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_1D874E3EF2B423396D62638CE970E2D9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_1D874E3EF2B423396D62638CE970E2D9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_6E69297ADBDF502E3082638CE9702A4A" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_6E69297ADBDF502E3082638CE9702A4A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_D0B72AB8423441CD5A7D638CE9714AF7" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_D0B72AB8423441CD5A7D638CE9714AF7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_38ECF80FAB889F071372638CE971B325" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_38ECF80FAB889F071372638CE971B325" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeIncludingSubsequentAcquisitionPercentage" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeIncludingSubsequentAcquisitionPercentage_8DBCBED9D5FAEF91E320638CE97183D5" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeIncludingSubsequentAcquisitionPercentage_8DBCBED9D5FAEF91E320638CE97183D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_214DEC3AA3412C68BECB638CE971E62E" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_214DEC3AA3412C68BECB638CE971E62E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationFiveYearCommitmentAnnualAmount" xlink:label="loc_viac_BusinessCombinationFiveYearCommitmentAnnualAmount_78BBF812D9E7C941E292638CEEBC08AD" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_viac_BusinessCombinationFiveYearCommitmentAnnualAmount_78BBF812D9E7C941E292638CEEBC08AD" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationFiveYearCommitmentTotal" xlink:label="loc_viac_BusinessCombinationFiveYearCommitmentTotal_459ACE385809B371E8CD638CE972C953" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_viac_BusinessCombinationFiveYearCommitmentTotal_459ACE385809B371E8CD638CE972C953" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationContingentConsiderationLiabilityPeriod" xlink:label="loc_viac_BusinessCombinationContingentConsiderationLiabilityPeriod_D9932F334D7A2AAC5965638CE9724953" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_viac_BusinessCombinationContingentConsiderationLiabilityPeriod_D9932F334D7A2AAC5965638CE9724953" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_64DE09AE79F9BDB27CFE638CE9729F10" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_64DE09AE79F9BDB27CFE638CE9729F10" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationAdditionOfTitlesToLibrary" xlink:label="loc_viac_BusinessCombinationAdditionOfTitlesToLibrary_0714C5528043077B5BCE638CE973F3CE" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_77F5F34E6F2FF0C5892D638CE96A77CE" xlink:to="loc_viac_BusinessCombinationAdditionOfTitlesToLibrary_0714C5528043077B5BCE638CE973F3CE" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestmentsInvestmentsNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_2AB22CA5C44E4D0C96BF63459333D8D4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_2AB22CA5C44E4D0C96BF63459333D8D4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_DECC44A842C19ABD9B056345933398E4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_2AB22CA5C44E4D0C96BF63459333D8D4" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_DECC44A842C19ABD9B056345933398E4_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_2AB22CA5C44E4D0C96BF63459333D8D4" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_DECC44A842C19ABD9B056345933398E4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_17A89B76D5D9E5C03F55634593331C99" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_DECC44A842C19ABD9B056345933398E4" xlink:to="loc_us-gaap_OtherAssetsMember_17A89B76D5D9E5C03F55634593331C99" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2B9819513804E7E913056345933408D9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2B9819513804E7E913056345933408D9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_951AE9F59BB91F79C7F063459334B04A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2B9819513804E7E913056345933408D9" xlink:to="loc_us-gaap_RelatedPartyDomain_951AE9F59BB91F79C7F063459334B04A_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_951AE9F59BB91F79C7F063459334B04A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_2B9819513804E7E913056345933408D9" xlink:to="loc_us-gaap_RelatedPartyDomain_951AE9F59BB91F79C7F063459334B04A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvesteeMember" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_06AFBB0E9B70E714B75E6345933515EE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_951AE9F59BB91F79C7F063459334B04A" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_06AFBB0E9B70E714B75E6345933515EE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipAxis" xlink:label="loc_srt_OwnershipAxis_D677358E01BDCE87E235634593359A8F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_srt_OwnershipAxis_D677358E01BDCE87E235634593359A8F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_D677358E01BDCE87E235634593359A8F" xlink:to="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_D677358E01BDCE87E235634593359A8F" xlink:to="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TheCWMember" xlink:label="loc_viac_TheCWMember_725804942E11E355C01F63459335699A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:to="loc_viac_TheCWMember_725804942E11E355C01F63459335699A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JointVentureWithAmcNetworksOneMember" xlink:label="loc_viac_JointVentureWithAmcNetworksOneMember_F3463BB00623001251B7634593364DF7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:to="loc_viac_JointVentureWithAmcNetworksOneMember_F3463BB00623001251B7634593364DF7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JointVentureWithAmcNetworksTwoMember" xlink:label="loc_viac_JointVentureWithAmcNetworksTwoMember_0844E5BCE46F02EB3C0763459336F171" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:to="loc_viac_JointVentureWithAmcNetworksTwoMember_0844E5BCE46F02EB3C0763459336F171" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_Viacom18Member" xlink:label="loc_viac_Viacom18Member_251FF938C2E742C5DAB363459336F3DC" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:to="loc_viac_Viacom18Member_251FF938C2E742C5DAB363459336F3DC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_EPIXMember" xlink:label="loc_viac_EPIXMember_D4AB209050265884628E6345933696CC" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_EC05028426EEABAE4CC863459335E710" xlink:to="loc_viac_EPIXMember_D4AB209050265884628E6345933696CC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_D7459ED3354B62B52ED163459337A226" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_D7459ED3354B62B52ED163459337A226" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_D7459ED3354B62B52ED163459337A226" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_D7459ED3354B62B52ED163459337A226" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_InternationalJointVentureMember" xlink:label="loc_viac_InternationalJointVentureMember_E8D02A04B506D200454C634593377AA2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521" xlink:to="loc_viac_InternationalJointVentureMember_E8D02A04B506D200454C634593377AA2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_Viacom18Member" xlink:label="loc_viac_Viacom18Member_3E550FEBECF2A50DBA60634593378EDB" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521" xlink:to="loc_viac_Viacom18Member_3E550FEBECF2A50DBA60634593378EDB" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_EPIXMember" xlink:label="loc_viac_EPIXMember_9764876A5D5555C7BEE163459338217F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_C1FBE8A9FC59D07F287963459337E521" xlink:to="loc_viac_EPIXMember_9764876A5D5555C7BEE163459338217F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C6725B0E312F9F0CF8BA634593388773" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C6725B0E312F9F0CF8BA634593388773" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A89F24DEFEA3917EDA9D6345933822DE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C6725B0E312F9F0CF8BA634593388773" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A89F24DEFEA3917EDA9D6345933822DE_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C6725B0E312F9F0CF8BA634593388773" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A89F24DEFEA3917EDA9D6345933822DE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_AE8C81F18FC2DACE17FD634593394DDC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A89F24DEFEA3917EDA9D6345933822DE" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_AE8C81F18FC2DACE17FD634593394DDC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_09D82F45E4E5AF1D3CF163459339B621" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F3F95003A50D07ACC7BA634593330957" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_09D82F45E4E5AF1D3CF163459339B621" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_280FE7838CA082397E2363459339AD34_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_09D82F45E4E5AF1D3CF163459339B621" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_280FE7838CA082397E2363459339AD34_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_09D82F45E4E5AF1D3CF163459339B621" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_280FE7838CA082397E2363459339AD34" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherItemsNetMember" xlink:label="loc_viac_OtherItemsNetMember_BD151CFD407B1497CCD1634593391DBC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_280FE7838CA082397E2363459339AD34" xlink:to="loc_viac_OtherItemsNetMember_BD151CFD407B1497CCD1634593391DBC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Investments" xlink:label="loc_us-gaap_Investments_0EDAEF7A2280FBFB46306345933A8B03" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_Investments_0EDAEF7A2280FBFB46306345933A8B03" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_B4DF3FF060E1224477BE6345933A482E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_B4DF3FF060E1224477BE6345933A482E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:label="loc_us-gaap_EquityMethodInvestments_301F0D4774E942D5369C6345933B81FE" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquityMethodInvestments_301F0D4774E942D5369C6345933B81FE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_7B3EA8575F485379D42E6345933B688B" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_7B3EA8575F485379D42E6345933B688B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketableSecurities" xlink:label="loc_us-gaap_MarketableSecurities_0E1EEB3003AA11C307606345933B2EF5" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_MarketableSecurities_0E1EEB3003AA11C307606345933B2EF5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:label="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_C65FAEC64F0FE1ABF1A16345933BC9FE" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_C65FAEC64F0FE1ABF1A16345933BC9FE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates" xlink:label="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_D69E8FAB2544E58CA7E06345933B8C13" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_D69E8FAB2544E58CA7E06345933B8C13" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromSaleOfEquityMethodInvestments" xlink:label="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments_C2F746EDCD254582B9686345933C7E1C" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments_C2F746EDCD254582B9686345933C7E1C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_722E8CECEA0E959CB3C66345933C91E0" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_722E8CECEA0E959CB3C66345933C91E0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount_3D0BAFAA58EC74C8F7536345933C73C0" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount_3D0BAFAA58EC74C8F7536345933C73C0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TransactionCostsDisposalOfEquityMethodInvestment" xlink:label="loc_viac_TransactionCostsDisposalOfEquityMethodInvestment_3EBC23055C2D2C4DD9046345933C33B3" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_viac_TransactionCostsDisposalOfEquityMethodInvestment_3EBC23055C2D2C4DD9046345933C33B3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions" xlink:label="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_14AF34D314130BF81B8A6345933D20D0" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7E6996D570F999A8CC656345933AE57D" xlink:to="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_14AF34D314130BF81B8A6345933D20D0" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestmentsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/AcquisitionAndInvestmentsVariableInterestEntitiesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableInterestEntityLineItems" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_F21FFB1CA88BED6AC16563459323BECF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_F21FFB1CA88BED6AC16563459323BECF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis" xlink:label="loc_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_E8FA8ED641905BCA3D4563459323D36C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_F21FFB1CA88BED6AC16563459323BECF" xlink:to="loc_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_E8FA8ED641905BCA3D4563459323D36C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassificationOfVariableInterestEntityDomain" xlink:label="loc_us-gaap_ClassificationOfVariableInterestEntityDomain_450EE728EC37AC12EDA963459324BE45_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_E8FA8ED641905BCA3D4563459323D36C" xlink:to="loc_us-gaap_ClassificationOfVariableInterestEntityDomain_450EE728EC37AC12EDA963459324BE45_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_E8FA8ED641905BCA3D4563459323D36C" xlink:to="loc_us-gaap_ClassificationOfVariableInterestEntityDomain_450EE728EC37AC12EDA963459324BE45" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_D1861E26655200B3F408634593245FEF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassificationOfVariableInterestEntityDomain_450EE728EC37AC12EDA963459324BE45" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_D1861E26655200B3F408634593245FEF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_FFD453D8D8B4546A514A63459324189F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_F21FFB1CA88BED6AC16563459323BECF" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_FFD453D8D8B4546A514A63459324189F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_59FE31AF9D80B57D993E63459325D295_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_FFD453D8D8B4546A514A63459324189F" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_59FE31AF9D80B57D993E63459325D295_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_FFD453D8D8B4546A514A63459324189F" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_59FE31AF9D80B57D993E63459325D295" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingAndBroadcastRightsMember" xlink:label="loc_us-gaap_OperatingAndBroadcastRightsMember_9F102BCB5AE342C7FA7C63459325E465" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_59FE31AF9D80B57D993E63459325D295" xlink:to="loc_us-gaap_OperatingAndBroadcastRightsMember_9F102BCB5AE342C7FA7C63459325E465" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets" xlink:label="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_FDB301E4896EBD3CE1E563459326FFB0" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_FDB301E4896EBD3CE1E563459326FFB0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableInterestEntityConsolidatedCarryingAmountLiabilities" xlink:label="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountLiabilities_3D92AD5298E31C2F28DA6345932639DA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountLiabilities_3D92AD5298E31C2F28DA6345932639DA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromSaleOfOtherAssetsInvestingActivities" xlink:label="loc_us-gaap_ProceedsFromSaleOfOtherAssetsInvestingActivities_AB7F7D087E7AC60C70BA634593266652" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_us-gaap_ProceedsFromSaleOfOtherAssetsInvestingActivities_AB7F7D087E7AC60C70BA634593266652" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainLossOnDispositionOfIntangibleAssets" xlink:label="loc_us-gaap_GainLossOnDispositionOfIntangibleAssets_6E42739EC59C79CA2A7E6345932608F6" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_us-gaap_GainLossOnDispositionOfIntangibleAssets_6E42739EC59C79CA2A7E6345932608F6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GainLossOnDispositionOfAssetsPortionAttributabletoNonControllingInterest" xlink:label="loc_viac_GainLossOnDispositionOfAssetsPortionAttributabletoNonControllingInterest_5A63133E06A46BBAEE7E63459327152F" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_0785156477AEB5768D39634593259A69" xlink:to="loc_viac_GainLossOnDispositionOfAssetsPortionAttributabletoNonControllingInterest_5A63133E06A46BBAEE7E63459327152F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPolicies" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesChangeInReportingEntityDetails" xlink:type="extended">

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_NameChangeEventLineItems" xlink:label="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:type="locator"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_NameChangeEventTable" xlink:label="loc_dei_NameChangeEventTable_09C96DC8835B834A31866345945B6583" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:to="loc_dei_NameChangeEventTable_09C96DC8835B834A31866345945B6583" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_5B040EFE1C08970387AB6345945C3B01" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_NameChangeEventTable_09C96DC8835B834A31866345945B6583" xlink:to="loc_dei_LegalEntityAxis_5B040EFE1C08970387AB6345945C3B01" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_11C1FEB8CD1C0EE043CC6345945C41D4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_5B040EFE1C08970387AB6345945C3B01" xlink:to="loc_dei_EntityDomain_11C1FEB8CD1C0EE043CC6345945C41D4_default" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_11C1FEB8CD1C0EE043CC6345945C41D4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_5B040EFE1C08970387AB6345945C3B01" xlink:to="loc_dei_EntityDomain_11C1FEB8CD1C0EE043CC6345945C41D4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_724A64AE3199576064E26345945C1EA3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_11C1FEB8CD1C0EE043CC6345945C41D4" xlink:to="loc_viac_ViacomIncMember_724A64AE3199576064E26345945C1EA3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ChangeinReportingEntityIncomeLossFromContinuingOperations" xlink:label="loc_viac_ChangeinReportingEntityIncomeLossFromContinuingOperations_E577DA7DB9B1F48267F06345945D955F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:to="loc_viac_ChangeinReportingEntityIncomeLossFromContinuingOperations_E577DA7DB9B1F48267F06345945D955F" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ChangeinReportingEntityEarningsPerShareBasic" xlink:label="loc_viac_ChangeinReportingEntityEarningsPerShareBasic_062B6BBABE0BB69556CD6345945DDBBB" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:to="loc_viac_ChangeinReportingEntityEarningsPerShareBasic_062B6BBABE0BB69556CD6345945DDBBB" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ChangeinReportingEntityEarningsPerShareDiluted" xlink:label="loc_viac_ChangeinReportingEntityEarningsPerShareDiluted_17E7687B4A50D42E04016345945DDA8F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:to="loc_viac_ChangeinReportingEntityEarningsPerShareDiluted_17E7687B4A50D42E04016345945DDA8F" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ChangeinReportingEntityOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_viac_ChangeinReportingEntityOtherComprehensiveIncomeLossNetOfTax_527975BCB6906FB1177D6345945E4D9D" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_NameChangeEventLineItems_6090608AA0D0A868B57F6345945DB453" xlink:to="loc_viac_ChangeinReportingEntityOtherComprehensiveIncomeLossNetOfTax_527975BCB6906FB1177D6345945E4D9D" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_BA4118682972915FA1896345947054DF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_BA4118682972915FA1896345947054DF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_95A051D9D0FB96FBCA4663459471CC77_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BA4118682972915FA1896345947054DF" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_95A051D9D0FB96FBCA4663459471CC77_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_95A051D9D0FB96FBCA4663459471CC77" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BA4118682972915FA1896345947054DF" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_95A051D9D0FB96FBCA4663459471CC77" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_C6316C8ADA2D14910FBB63459471C3CD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_95A051D9D0FB96FBCA4663459471CC77" xlink:to="loc_viac_ViacomIncMember_C6316C8ADA2D14910FBB63459471C3CD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_6B2B0A6F8FDF127916B56345947193FE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_StatementClassOfStockAxis_6B2B0A6F8FDF127916B56345947193FE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_EE697B8CAB0F9E7EAB03634594727F63_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6B2B0A6F8FDF127916B56345947193FE" xlink:to="loc_us-gaap_ClassOfStockDomain_EE697B8CAB0F9E7EAB03634594727F63_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6B2B0A6F8FDF127916B56345947193FE" xlink:to="loc_us-gaap_ClassOfStockDomain_EE697B8CAB0F9E7EAB03634594727F63" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_6AF53C592C4E2274D058634594723D6D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_EE697B8CAB0F9E7EAB03634594727F63" xlink:to="loc_us-gaap_CommonClassAMember_6AF53C592C4E2274D058634594723D6D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_BC51DCB730D089F5CFF163459472805F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_EE697B8CAB0F9E7EAB03634594727F63" xlink:to="loc_us-gaap_CommonClassBMember_BC51DCB730D089F5CFF163459472805F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_AA10579286C40D78945463459475C0D8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_AA10579286C40D78945463459475C0D8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_AA10579286C40D78945463459475C0D8" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_AA10579286C40D78945463459475C0D8" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_450A0E6CC363C73D081E634594906FF1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_450A0E6CC363C73D081E634594906FF1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_6CF00A8BAA84ABA4D8F66345949181ED" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_65D6A1077EA290BCB3326345949012F8" xlink:to="loc_us-gaap_OtherAssetsMember_6CF00A8BAA84ABA4D8F66345949181ED" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_36CF09BF8E49330B519D63459491C5E5" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_srt_ProductOrServiceAxis_36CF09BF8E49330B519D63459491C5E5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_36CF09BF8E49330B519D63459491C5E5" xlink:to="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_36CF09BF8E49330B519D63459491C5E5" xlink:to="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FeatureFilmMember" xlink:label="loc_viac_FeatureFilmMember_23014B96EE8A9D35834C634594925409" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402" xlink:to="loc_viac_FeatureFilmMember_23014B96EE8A9D35834C634594925409" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmLibrariesAcquiredMember" xlink:label="loc_viac_FilmLibrariesAcquiredMember_699BAB531B1141B6CB03634594920A14" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402" xlink:to="loc_viac_FilmLibrariesAcquiredMember_699BAB531B1141B6CB03634594920A14" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TelevisionLicensingMember" xlink:label="loc_viac_TelevisionLicensingMember_687A961D84234850D2D66345949389E5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_0E1A19F90C17C86A7DCD634594916402" xlink:to="loc_viac_TelevisionLicensingMember_687A961D84234850D2D66345949389E5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_8F2DCD2695788D26A570634594936D30" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_srt_RangeAxis_8F2DCD2695788D26A570634594936D30" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8F2DCD2695788D26A570634594936D30" xlink:to="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8F2DCD2695788D26A570634594936D30" xlink:to="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_7997139F071B3D13AFAB634594946E88" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A" xlink:to="loc_srt_MinimumMember_7997139F071B3D13AFAB634594946E88" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_7EA142C68DE25E84D93B63459495F8FA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_499576276252AEDCCF7063459494E86A" xlink:to="loc_srt_MaximumMember_7EA142C68DE25E84D93B63459495F8FA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_41A07DE0BCAC73C28025634594959B35" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_41A07DE0BCAC73C28025634594959B35" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_B581763F05730F2C42E96345949556D6_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_41A07DE0BCAC73C28025634594959B35" xlink:to="loc_us-gaap_EquityComponentDomain_B581763F05730F2C42E96345949556D6_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_41A07DE0BCAC73C28025634594959B35" xlink:to="loc_us-gaap_EquityComponentDomain_B581763F05730F2C42E96345949556D6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_4D441F57B4DAF2CFAAA86345949626E1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_B581763F05730F2C42E96345949556D6" xlink:to="loc_us-gaap_RetainedEarningsMember_4D441F57B4DAF2CFAAA86345949626E1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_83B71488C2849AB71EF363459496DE04" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_83B71488C2849AB71EF363459496DE04" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_6089330D193BBF1500BC6345949751F3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_83B71488C2849AB71EF363459496DE04" xlink:to="loc_us-gaap_TypeOfAdoptionMember_6089330D193BBF1500BC6345949751F3_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_83B71488C2849AB71EF363459496DE04" xlink:to="loc_us-gaap_TypeOfAdoptionMember_6089330D193BBF1500BC6345949751F3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_EB74B1758C0DAA128028634594979C1B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_6089330D193BBF1500BC6345949751F3" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_EB74B1758C0DAA128028634594979C1B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_5140EDD6EFE4E7045EF063459497D09E" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DEEE607ADB0ADB15E6C86345946F0162" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_5140EDD6EFE4E7045EF063459497D09E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7E8F3F45FD3B18045F826345949801E6_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_5140EDD6EFE4E7045EF063459497D09E" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7E8F3F45FD3B18045F826345949801E6_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_5140EDD6EFE4E7045EF063459497D09E" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7E8F3F45FD3B18045F826345949801E6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockOptionsAndRestrictedStockUnitsMember" xlink:label="loc_viac_StockOptionsAndRestrictedStockUnitsMember_A04F83C3449884A30841634594984AB3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7E8F3F45FD3B18045F826345949801E6" xlink:to="loc_viac_StockOptionsAndRestrictedStockUnitsMember_A04F83C3449884A30841634594984AB3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_UltimateRevenuePeriodRevenueIsEarned" xlink:label="loc_viac_UltimateRevenuePeriodRevenueIsEarned_1FA50315C9D4F6AFB697634594999772" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_viac_UltimateRevenuePeriodRevenueIsEarned_1FA50315C9D4F6AFB697634594999772" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio" xlink:label="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_99A245D87F73F7F2F40C634594999DD5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_99A245D87F73F7F2F40C634594999DD5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmDevelopmentCostsExpensePeriod" xlink:label="loc_viac_FilmDevelopmentCostsExpensePeriod_D55AC1F12E30423503FF6345949A155D" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_viac_FilmDevelopmentCostsExpensePeriod_D55AC1F12E30423503FF6345949A155D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract_B2B2CB0194F6921C3A586345949A04F2" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract_B2B2CB0194F6921C3A586345949A04F2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_3580D8295606E56E96606345949AFDCD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract_B2B2CB0194F6921C3A586345949A04F2" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_3580D8295606E56E96606345949AFDCD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwillAbstract" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwillAbstract_19E4B8F9909E3C52721A6345949BFCF0" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwillAbstract_19E4B8F9909E3C52721A6345949BFCF0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_4D5BC4A867AA869297066345949BC619" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntangibleAssetsNetIncludingGoodwillAbstract_19E4B8F9909E3C52721A6345949BFCF0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_4D5BC4A867AA869297066345949BC619" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AllowanceForSalesReturnsAndAllowances" xlink:label="loc_viac_AllowanceForSalesReturnsAndAllowances_AF5A95E54E0BCA79B19A634594B2774D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_viac_AllowanceForSalesReturnsAndAllowances_AF5A95E54E0BCA79B19A634594B2774D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D953F01837738CA75FE0634594B2641F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D953F01837738CA75FE0634594B2641F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_39298042DCAF60616640634594B34818" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_39298042DCAF60616640634594B34818" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ContentLicensingAndDistributionCollectionTerm" xlink:label="loc_viac_ContentLicensingAndDistributionCollectionTerm_165B1CAF93F54CEC90FB634594B3018A" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_viac_ContentLicensingAndDistributionCollectionTerm_165B1CAF93F54CEC90FB634594B3018A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsReceivableNetNoncurrent" xlink:label="loc_us-gaap_AccountsReceivableNetNoncurrent_0A2A104F0A39B4A04187634594B3BFDA" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_AccountsReceivableNetNoncurrent_0A2A104F0A39B4A04187634594B3BFDA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="loc_us-gaap_ContractWithCustomerLiability_3493A175898C6CFFE00A634594B3C867" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_ContractWithCustomerLiability_3493A175898C6CFFE00A634594B3C867" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_C87096CCEC4F9DDD91F2634594B48B3C" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_C87096CCEC4F9DDD91F2634594B48B3C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod" xlink:label="loc_us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_B835CC46B1F9F5BCCBA7634594B48A93" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0383F2854F3F550450F2634594B2151B" xlink:to="loc_us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_B835CC46B1F9F5BCCBA7634594B48A93" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleRetrospectiveAdjustmentsAbstract" xlink:label="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleRetrospectiveAdjustmentsAbstract_E87C84B71EF829E8FCB4634594B5F372" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleRetrospectiveAdjustmentsAbstract_E87C84B71EF829E8FCB4634594B5F372" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D223EE92792186945EED634594B599C9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleRetrospectiveAdjustmentsAbstract_E87C84B71EF829E8FCB4634594B5F372" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D223EE92792186945EED634594B599C9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="loc_us-gaap_LeasesAbstract_F77D0BE9A09FF81A7F42634594B5E312" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_LeasesAbstract_F77D0BE9A09FF81A7F42634594B5E312" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_B5002BD06B2A0A40FB1A634594B511A3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeasesAbstract_F77D0BE9A09FF81A7F42634594B5E312" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_B5002BD06B2A0A40FB1A634594B511A3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_6FF0FABC5EB9CC1EE98E634594B611F6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeasesAbstract_F77D0BE9A09FF81A7F42634594B5E312" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_6FF0FABC5EB9CC1EE98E634594B611F6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketingAndAdvertisingExpenseAbstract" xlink:label="loc_us-gaap_MarketingAndAdvertisingExpenseAbstract_556738A69DBF4294D9B5634594B6BB06" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_MarketingAndAdvertisingExpenseAbstract_556738A69DBF4294D9B5634594B6BB06" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdvertisingExpense" xlink:label="loc_us-gaap_AdvertisingExpense_5C46A80AB4D7B582FC0F634594B77091" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketingAndAdvertisingExpenseAbstract_556738A69DBF4294D9B5634594B6BB06" xlink:to="loc_us-gaap_AdvertisingExpense_5C46A80AB4D7B582FC0F634594B77091" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_6629914B00195E5463DE634594B7389B" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_A4C6194D2A07A2FC6C63634594994267" xlink:to="loc_us-gaap_EarningsPerShareAbstract_6629914B00195E5463DE634594B7389B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_9D33C8D0DD405DA2C427634594B7BD45" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_6629914B00195E5463DE634594B7389B" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_9D33C8D0DD405DA2C427634594B7BD45" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNetEarningsLossPerCommonShareDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_C7D68E51916FB9D76EF063459453F685" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F5FEFED343B2435C55BA6345944F283D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_C7D68E51916FB9D76EF063459453F685" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F5FEFED343B2435C55BA6345944F283D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_B898926C130D29EAB20D634594502C7B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F5FEFED343B2435C55BA6345944F283D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_B898926C130D29EAB20D634594502C7B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_B898926C130D29EAB20D634594502C7B" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_B898926C130D29EAB20D634594502C7B" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_E6111EC01E57D99010EA634594513BC1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66" xlink:to="loc_us-gaap_BuildingMember_E6111EC01E57D99010EA634594513BC1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_05D759FF5477B98BD916634594514534" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_05D759FF5477B98BD916634594514534" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember" xlink:label="loc_us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember_55AD89BD55CDA127480D634594528E8B" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C284BA1EEEBE6A628ADB634594507C66" xlink:to="loc_us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember_55AD89BD55CDA127480D634594528E8B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_6B7B7156995620A4FA9B63459452F0C5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F5FEFED343B2435C55BA6345944F283D" xlink:to="loc_srt_RangeAxis_6B7B7156995620A4FA9B63459452F0C5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6B7B7156995620A4FA9B63459452F0C5" xlink:to="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6B7B7156995620A4FA9B63459452F0C5" xlink:to="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_F854A556D834B624A3ED63459452479C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF" xlink:to="loc_srt_MinimumMember_F854A556D834B624A3ED63459452479C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_1853A47723DCC951491C63459453C98D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_06F84C0EA6B97A09CF3B63459452A3FF" xlink:to="loc_srt_MaximumMember_1853A47723DCC951491C63459453C98D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_B83BC19291DCE10445D763459454DF75" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_C7D68E51916FB9D76EF063459453F685" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_B83BC19291DCE10445D763459454DF75" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_AB8F624418B7DD2696D8634594545448" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_C7D68E51916FB9D76EF063459453F685" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_AB8F624418B7DD2696D8634594545448" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsNarrativeDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesUnrecognizedRevenuesUnderContractDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_7FE5040C4F0CFEFA0D2A63459445FDAA" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_66AAF2A64F5BE26C4A25634594441D6F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_7FE5040C4F0CFEFA0D2A63459445FDAA" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_66AAF2A64F5BE26C4A25634594441D6F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_FD5386E7BD94886EE1CF634594454A33" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_66AAF2A64F5BE26C4A25634594441D6F" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_FD5386E7BD94886EE1CF634594454A33" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_08345DC36314CED19091634594462F05" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_7FE5040C4F0CFEFA0D2A63459445FDAA" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_08345DC36314CED19091634594462F05" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CommitmentsAndContingencies" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CommitmentsAndContingenciesCommitmentsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CommitmentsAndContingenciesLegalMattersNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_7BAFEBC5667BD9E60DE463458E86D6A0" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_us-gaap_LossContingenciesTable_7BAFEBC5667BD9E60DE463458E86D6A0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_LitigationCaseAxis" xlink:label="loc_srt_LitigationCaseAxis_BCBEF1A9BC0C0BDF903463458E879F00" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_7BAFEBC5667BD9E60DE463458E86D6A0" xlink:to="loc_srt_LitigationCaseAxis_BCBEF1A9BC0C0BDF903463458E879F00" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:label="loc_srt_LitigationCaseTypeDomain_ED6734220B7D851FFDC863458E87CA1F_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_BCBEF1A9BC0C0BDF903463458E879F00" xlink:to="loc_srt_LitigationCaseTypeDomain_ED6734220B7D851FFDC863458E87CA1F_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_BCBEF1A9BC0C0BDF903463458E879F00" xlink:to="loc_srt_LitigationCaseTypeDomain_ED6734220B7D851FFDC863458E87CA1F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AsbestosIssueMember" xlink:label="loc_us-gaap_AsbestosIssueMember_5F6A12F3A40ECF97F34663458E8703E8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_ED6734220B7D851FFDC863458E87CA1F" xlink:to="loc_us-gaap_AsbestosIssueMember_5F6A12F3A40ECF97F34663458E8703E8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_CDFA9BB3A40D967F673363458E883736" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_7BAFEBC5667BD9E60DE463458E86D6A0" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_CDFA9BB3A40D967F673363458E883736" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1A80C924A214E73B214A63458E8859DA_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_CDFA9BB3A40D967F673363458E883736" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1A80C924A214E73B214A63458E8859DA_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_CDFA9BB3A40D967F673363458E883736" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1A80C924A214E73B214A63458E8859DA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_8ECED2900D5AF497469463458E884E78" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_1A80C924A214E73B214A63458E8859DA" xlink:to="loc_us-gaap_SubsequentEventMember_8ECED2900D5AF497469463458E884E78" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_NumberOfConsolidatedCassActionLawsuits" xlink:label="loc_viac_NumberOfConsolidatedCassActionLawsuits_85980F2100CD7F12F20D63458E8E6D21" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_viac_NumberOfConsolidatedCassActionLawsuits_85980F2100CD7F12F20D63458E8E6D21" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ContributionsToGrantorTrust" xlink:label="loc_viac_ContributionsToGrantorTrust_C8D39F2421488309C35063458E8E6914" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_viac_ContributionsToGrantorTrust_C8D39F2421488309C35063458E8E6914" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_0FA7D9E22B20F7EDD1EA63458E8EE260" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_0FA7D9E22B20F7EDD1EA63458E8EE260" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingencyNewClaimsFiledNumber" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_D4A332B15ED8B52907DA63458E8FB470" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_D4A332B15ED8B52907DA63458E8FB470" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingencyClaimsSettledAndDismissedNumber" xlink:label="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_E88C7A12E75D41C61F9263458E8F2535" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_E88C7A12E75D41C61F9263458E8F2535" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsNetIncurredLoss1" xlink:label="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsNetIncurredLoss1_ECE1D54F22AE3CCE7F1C63458E8F2619" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_33684FCF9A7926A53DF463458E892AAC" xlink:to="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsNetIncurredLoss1_ECE1D54F22AE3CCE7F1C63458E8F2619" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CommitmentsAndContingenciesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsTable" xlink:label="loc_us-gaap_OtherCommitmentsTable_2F25AC0E922D1A8CBE4163458EDF93F1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_us-gaap_OtherCommitmentsTable_2F25AC0E922D1A8CBE4163458EDF93F1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsAxis" xlink:label="loc_us-gaap_OtherCommitmentsAxis_F4C0FDCAE5EF70ABFF8463458EDFA0A1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_2F25AC0E922D1A8CBE4163458EDF93F1" xlink:to="loc_us-gaap_OtherCommitmentsAxis_F4C0FDCAE5EF70ABFF8463458EDFA0A1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OtherCommitmentsAxis_F4C0FDCAE5EF70ABFF8463458EDFA0A1" xlink:to="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OtherCommitmentsAxis_F4C0FDCAE5EF70ABFF8463458EDFA0A1" xlink:to="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SportsProgrammingRightsCommitmentsMember" xlink:label="loc_viac_SportsProgrammingRightsCommitmentsMember_1834D45DE59963B794FB63458EE0752E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156" xlink:to="loc_viac_SportsProgrammingRightsCommitmentsMember_1834D45DE59963B794FB63458EE0752E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProductionLicensingOfProgrammingMember" xlink:label="loc_viac_ProductionLicensingOfProgrammingMember_34664BCAF04C9B40682263458EE1736F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156" xlink:to="loc_viac_ProductionLicensingOfProgrammingMember_34664BCAF04C9B40682263458EE1736F" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TalentContractsMember" xlink:label="loc_viac_TalentContractsMember_FDF600CFF517D9E2CB5A63458EE1E918" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_16C85FF5382F97E8AF7163458EE0B156" xlink:to="loc_viac_TalentContractsMember_FDF600CFF517D9E2CB5A63458EE1E918" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_23CEEFA17951B17DBC3263458EE1E820" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_2F25AC0E922D1A8CBE4163458EDF93F1" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_23CEEFA17951B17DBC3263458EE1E820" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_0CD35DB85FACFB5013BE63458EE1885D_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_23CEEFA17951B17DBC3263458EE1E820" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_0CD35DB85FACFB5013BE63458EE1885D_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_23CEEFA17951B17DBC3263458EE1E820" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_0CD35DB85FACFB5013BE63458EE1885D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSTelevisionCityMember" xlink:label="loc_viac_CBSTelevisionCityMember_0247AD5E23003780034B63458EE2E285" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_0CD35DB85FACFB5013BE63458EE1885D" xlink:to="loc_viac_CBSTelevisionCityMember_0247AD5E23003780034B63458EE2E285" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FamousPlayersMember" xlink:label="loc_viac_FamousPlayersMember_09CD96E33EDB5D701F9E63458EE29CD7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_0CD35DB85FACFB5013BE63458EE1885D" xlink:to="loc_viac_FamousPlayersMember_09CD96E33EDB5D701F9E63458EE29CD7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitment" xlink:label="loc_us-gaap_OtherCommitment_F5BE1E72C86ACFAF294363458EE35A91" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_us-gaap_OtherCommitment_F5BE1E72C86ACFAF294363458EE35A91" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount" xlink:label="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_EF2860E3C4586592F94463458EE34604" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_EF2860E3C4586592F94463458EE34604" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_56ED45807D5CAABE07D463458EE352A2" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_56ED45807D5CAABE07D463458EE352A2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_E37EF2480195C68D9BBA63458EE36101" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_E37EF2480195C68D9BBA63458EE36101" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GuaranteedCashFlowPeriod" xlink:label="loc_viac_GuaranteedCashFlowPeriod_600770A40826FDEF087163458EE38AAC" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_643547F054BD7469D58163458EE2509D" xlink:to="loc_viac_GuaranteedCashFlowPeriod_600770A40826FDEF087163458EE38AAC" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CommitmentsAndContingenciesTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedBalanceSheets" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_9D9C315F03FA15F5A2AC634595AB43DD" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_C265EEF301F008FDA09A634595A95D60" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_9D9C315F03FA15F5A2AC634595AB43DD" xlink:to="loc_us-gaap_StatementTable_C265EEF301F008FDA09A634595A95D60" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_B1322FB75E1A5E8AA038634595AA7FF6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_C265EEF301F008FDA09A634595A95D60" xlink:to="loc_us-gaap_StatementClassOfStockAxis_B1322FB75E1A5E8AA038634595AA7FF6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_B1322FB75E1A5E8AA038634595AA7FF6" xlink:to="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_B1322FB75E1A5E8AA038634595AA7FF6" xlink:to="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_71A25E56C4EE1F6905E1634595AA6588" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A" xlink:to="loc_us-gaap_CommonClassAMember_71A25E56C4EE1F6905E1634595AA6588" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_8C7E570783DDDC2EEFBC634595AB9ECA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_CA28817B1FC3599EF1D5634595AA6E8A" xlink:to="loc_us-gaap_CommonClassBMember_8C7E570783DDDC2EEFBC634595AB9ECA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_9D9C315F03FA15F5A2AC634595AB43DD" xlink:to="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_58726D2D55D80630C9C5634595AC5AAD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_58726D2D55D80630C9C5634595AC5AAD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_92003F28194FBA5A69BF634595AC9949" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_92003F28194FBA5A69BF634595AC9949" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_491E0E4E0CD510E95559634595AD5E5F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_InventoryNet_491E0E4E0CD510E95559634595AD5E5F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="loc_us-gaap_PrepaidExpenseCurrent_1657B998E228303945F4634595AD8ECE" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_PrepaidExpenseCurrent_1657B998E228303945F4634595AD8ECE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_0AA867CA1F251C2EB622634595AD3173" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_OtherAssetsCurrent_0AA867CA1F251C2EB622634595AD3173" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_A2BC8A77D1C680F53412634595AD5CD3" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_19895C5F7350C80CA8E1634595AC654B" xlink:to="loc_us-gaap_AssetsCurrent_A2BC8A77D1C680F53412634595AD5CD3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:label="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization_B7A5334ECD1CFE669862634595ADB720" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization_B7A5334ECD1CFE669862634595ADB720" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InventoryNoncurrent" xlink:label="loc_us-gaap_InventoryNoncurrent_5E624B6D2E2ACDACB797634595AE35B3" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_InventoryNoncurrent_5E624B6D2E2ACDACB797634595AE35B3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_A2AD439390EA39A0CA29634595AE5013" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_Goodwill_A2AD439390EA39A0CA29634595AE5013" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_55F8502BE922BFCE362E634595AE6FD3" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_55F8502BE922BFCE362E634595AE6FD3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_843214A2DFAAD04FAF72634595AE9C7C" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_843214A2DFAAD04FAF72634595AE9C7C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_C114A621CF4A7F429B58634595AF4B3F" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_C114A621CF4A7F429B58634595AF4B3F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_55DFE07DD032B1B929FF634595AF4AEE" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_55DFE07DD032B1B929FF634595AF4AEE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AssetsHeldForSaleNoncurrent" xlink:label="loc_viac_AssetsHeldForSaleNoncurrent_30C230A6929E205BEB51634595AFAA8A" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_viac_AssetsHeldForSaleNoncurrent_30C230A6929E205BEB51634595AFAA8A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_8D779EAAD53B55FF5D54634595AFB8E8" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_C4DEFEB3E958EE9C6E99634595ABDD27" xlink:to="loc_us-gaap_Assets_8D779EAAD53B55FF5D54634595AFB8E8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_9D9C315F03FA15F5A2AC634595AB43DD" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_B745BD10C030EF215C03634595B03A73" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_AccountsPayableCurrent_B745BD10C030EF215C03634595B03A73" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_B4A772866567F18BB0A2634595B16D6A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_B4A772866567F18BB0A2634595B16D6A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccruedRoyaltiesCurrent" xlink:label="loc_us-gaap_AccruedRoyaltiesCurrent_185DC018F811C83EFFB6634595B16D0E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_AccruedRoyaltiesCurrent_185DC018F811C83EFFB6634595B16D0E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProgramRightsObligationsCurrent" xlink:label="loc_us-gaap_ProgramRightsObligationsCurrent_4C6F43B6C1BFCEFB3491634595B1EE7F" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_ProgramRightsObligationsCurrent_4C6F43B6C1BFCEFB3491634595B1EE7F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_01AEE1B80CB60A14D4AB634595B17772" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_01AEE1B80CB60A14D4AB634595B17772" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_us-gaap_DebtCurrent_D0DFF0CD054A472988E5634595B2DEBF" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_DebtCurrent_D0DFF0CD054A472988E5634595B2DEBF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_79A843BD9D14E6A815B4634595B28EEE" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_79A843BD9D14E6A815B4634595B28EEE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_FA03ECDD14803E7EB256634595B20214" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_EE5BB61F626B982154CA634595B051D6" xlink:to="loc_us-gaap_LiabilitiesCurrent_FA03ECDD14803E7EB256634595B20214" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_30CE14BAB1C8C7FF0543634595B2FA7D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_30CE14BAB1C8C7FF0543634595B2FA7D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AccruedRoyaltiesNoncurrent" xlink:label="loc_viac_AccruedRoyaltiesNoncurrent_4B2B8CA0EC2E501B6B21634595B25BEA" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_viac_AccruedRoyaltiesNoncurrent_4B2B8CA0EC2E501B6B21634595B25BEA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_5652899514D138A8EDDA634595B8F7B9" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_5652899514D138A8EDDA634595B8F7B9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_F085ABF9D0FB3A0B6E0E634595B8BCC9" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_F085ABF9D0FB3A0B6E0E634595B8BCC9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_43701C46A7A08800FA41634595B95AE1" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_43701C46A7A08800FA41634595B95AE1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProgramRightsObligationsNoncurrent" xlink:label="loc_us-gaap_ProgramRightsObligationsNoncurrent_7435DA1A5808E77D3523634595B91613" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_ProgramRightsObligationsNoncurrent_7435DA1A5808E77D3523634595B91613" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_91BF955B67733218F9C6634595B97FDE" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_91BF955B67733218F9C6634595B97FDE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_9DBAB9B8DCFE254469F8634595B9E90B" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_9DBAB9B8DCFE254469F8634595B9E90B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_075B03B20ECF5681E9A1634595B91BB7" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_CommitmentsAndContingencies_075B03B20ECF5681E9A1634595B91BB7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_DB1EC7B1F389808F1A97634595BAD4E8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_CommonStockValue_DB1EC7B1F389808F1A97634595BAD4E8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_86A1AF53173CF697BF0D634595BAA6AA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_86A1AF53173CF697BF0D634595BAA6AA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_us-gaap_TreasuryStockValue_0D60355A51C934B229A1634595BA97F8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_TreasuryStockValue_0D60355A51C934B229A1634595BA97F8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_A084E10E90F0F4301130634595BB4159" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_A084E10E90F0F4301130634595BB4159" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8D3B522E24D280044670634595BB496F" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8D3B522E24D280044670634595BB496F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_1D798B00679D6A34D40E634595BB97CD" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_7C5F3D3E29CBECC584BE634595B92490" xlink:to="loc_us-gaap_StockholdersEquity_1D798B00679D6A34D40E634595BB97CD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MinorityInterest" xlink:label="loc_us-gaap_MinorityInterest_A19AFD3DA2D63EB1CF59634595BBF166" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_MinorityInterest_A19AFD3DA2D63EB1CF59634595BBF166" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_CD7713047F5015509DA8634595BB1980" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_CD7713047F5015509DA8634595BB1980" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_A400711DDBD39C30ACEB634595BC2BA2" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_44480CF759F293A49918634595B0FBB2" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_A400711DDBD39C30ACEB634595BC2BA2" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_9F2A9F8AB86C67065EA063459575B7DC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:to="loc_us-gaap_StatementTable_9F2A9F8AB86C67065EA063459575B7DC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_1E292C095F5F8B2E6C3763459576D076" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_9F2A9F8AB86C67065EA063459575B7DC" xlink:to="loc_us-gaap_StatementClassOfStockAxis_1E292C095F5F8B2E6C3763459576D076" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1E292C095F5F8B2E6C3763459576D076" xlink:to="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1E292C095F5F8B2E6C3763459576D076" xlink:to="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_9710E3A16C65EAD049A963459577F41E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6" xlink:to="loc_us-gaap_CommonClassAMember_9710E3A16C65EAD049A963459577F41E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_747CEC6EB855B3A0602D634595775856" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_CEC972C0CB6A7395A87363459576C1A6" xlink:to="loc_us-gaap_CommonClassBMember_747CEC6EB855B3A0602D634595775856" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_8C6724731877B1EB18E563459577C9E1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_8C6724731877B1EB18E563459577C9E1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_CC7A4CFDB0B0CD220D4E6345957884BE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_CC7A4CFDB0B0CD220D4E6345957884BE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_47569AB92AD3A4FF286163459578607F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:to="loc_us-gaap_CommonStockSharesIssued_47569AB92AD3A4FF286163459578607F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="loc_us-gaap_TreasuryStockShares_98088A4EBE52D4D7F1D1634595788C74" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_A21CC5B42C7F729D8F25634595770E0D" xlink:to="loc_us-gaap_TreasuryStockShares_98088A4EBE52D4D7F1D1634595788C74" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedStatementsOfCashFlowsParenthetical" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_7FB5C28BECC38E594DF663A42FC14197" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_E05ABCF587DE0929EADD63A42FBCFDFF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_7FB5C28BECC38E594DF663A42FC14197" xlink:to="loc_us-gaap_StatementTable_E05ABCF587DE0929EADD63A42FBCFDFF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_F64609D112E2883DAD6E63A42FBECF34" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_E05ABCF587DE0929EADD63A42FBCFDFF" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_F64609D112E2883DAD6E63A42FBECF34" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_F64609D112E2883DAD6E63A42FBECF34" xlink:to="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_F64609D112E2883DAD6E63A42FBECF34" xlink:to="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_3A7507480ED9D2BEBED263A42FBF9881" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_CommonStockMember_3A7507480ED9D2BEBED263A42FBF9881" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember_D690182C5FFB81A435B963A42FC0EEE6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_TreasuryStockMember_D690182C5FFB81A435B963A42FC0EEE6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_52346D573FD95DD542AA63A42FC06C69" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_52346D573FD95DD542AA63A42FC06C69" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_115CA64CD48AAA6BF23A63A42FC0C302" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_RetainedEarningsMember_115CA64CD48AAA6BF23A63A42FC0C302" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3146441FED2051CB4B9763A42FC15B0C" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3146441FED2051CB4B9763A42FC15B0C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ParentMember" xlink:label="loc_us-gaap_ParentMember_FC9E46BFB78DDF270CAB63A42FC1F0AB" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_ParentMember_FC9E46BFB78DDF270CAB63A42FC1F0AB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:label="loc_us-gaap_NoncontrollingInterestMember_DBFB1412654C7BE9506963A42FC1F25D" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91F6913A793D73AEEBD163A42FBE2AD8" xlink:to="loc_us-gaap_NoncontrollingInterestMember_DBFB1412654C7BE9506963A42FC1F25D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_7FB5C28BECC38E594DF663A42FC14197" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_4CC37BA311C3CC33E6EA63A42FC7AE9A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_SharesIssued_4CC37BA311C3CC33E6EA63A42FC7AE9A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_C2CC74021EEF06BFE14463A42FC776E2" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_C2CC74021EEF06BFE14463A42FC776E2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_CB4A2205AE90AAD5AD8E63A42FC82C03" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_CB4A2205AE90AAD5AD8E63A42FC82C03" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_496763DBE00962E3658963A42FC8AB2F" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_496763DBE00962E3658963A42FC8AB2F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockSharesRetired" xlink:label="loc_us-gaap_TreasuryStockSharesRetired_A4298A9A6BB44DD1555463A42FCCF6DF" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_TreasuryStockSharesRetired_A4298A9A6BB44DD1555463A42FCCF6DF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockRetiredCostMethodAmount" xlink:label="loc_us-gaap_TreasuryStockRetiredCostMethodAmount_FA1E8B94790C6A2FFAE863A42FCC60D5" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_TreasuryStockRetiredCostMethodAmount_FA1E8B94790C6A2FFAE863A42FCC60D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_A1B7F7D073E5094CD1EF63A42FCC180B" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_A1B7F7D073E5094CD1EF63A42FCC180B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_A6B113897EF2D1A5124363A42FCC1BD2" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_A6B113897EF2D1A5124363A42FCC1BD2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CompanyStockReceivedInSplitOffTransactionShares" xlink:label="loc_viac_CompanyStockReceivedInSplitOffTransactionShares_A04EFC5B732A4242D5A863A42FCDF6AC" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_viac_CompanyStockReceivedInSplitOffTransactionShares_A04EFC5B732A4242D5A863A42FCDF6AC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockholdersEquityNoteSplitOffTransaction" xlink:label="loc_viac_StockholdersEquityNoteSplitOffTransaction_302027F9E6168900840263A42FCDE53C" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_viac_StockholdersEquityNoteSplitOffTransaction_302027F9E6168900840263A42FCDE53C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_EE695DFA66C60CD7AC9063A42FCD0A3B" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_EE695DFA66C60CD7AC9063A42FCD0A3B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_NoncontrollingInterest" xlink:label="loc_viac_NoncontrollingInterest_415DCB6EBB90E31E58B963A7DAFDFDE0" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_viac_NoncontrollingInterest_415DCB6EBB90E31E58B963A7DAFDFDE0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_EAA30E27AB68468DED8663A42FCE0D1F" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_ProfitLoss_EAA30E27AB68468DED8663A42FCE0D1F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_4268566D3229691F21E863A42FCE5A1A" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_4268566D3229691F21E863A42FCE5A1A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect_624235FEF772F29CB26663A42FCE016F" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect_624235FEF772F29CB26663A42FCE016F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_20A06DFCFD5E6B686FCE63A42FCE8378" xlink:type="locator"/>

<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_22E783C9D47D159482FA63A42FC71D7D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_20A06DFCFD5E6B686FCE63A42FCE8378" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/CoverPage" xlink:type="extended">

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentInformationLineItems" xlink:label="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:type="locator"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentInformationTable" xlink:label="loc_dei_DocumentInformationTable_A5B92C34733A3D0BF5CA63459626CC70" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentInformationTable_A5B92C34733A3D0BF5CA63459626CC70" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_D9D409A91E17C132DB7B63459627E7F9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_A5B92C34733A3D0BF5CA63459626CC70" xlink:to="loc_us-gaap_StatementClassOfStockAxis_D9D409A91E17C132DB7B63459627E7F9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_D9D409A91E17C132DB7B63459627E7F9" xlink:to="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_D9D409A91E17C132DB7B63459627E7F9" xlink:to="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_683A9CAC6A8561D56716634596280AC9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327" xlink:to="loc_us-gaap_CommonClassAMember_683A9CAC6A8561D56716634596280AC9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_88E57E1AB716FB22FF716345962815FF" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3E9F6D5BDB52BCC4C08463459627A327" xlink:to="loc_us-gaap_CommonClassBMember_88E57E1AB716FB22FF716345962815FF" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_301EB4D8AAE5A9AA45C463459628F86F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentType_301EB4D8AAE5A9AA45C463459628F86F" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentAnnualReport" xlink:label="loc_dei_DocumentAnnualReport_7CA983442C9924265E056345962930BE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentAnnualReport_7CA983442C9924265E056345962930BE" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_1962C5B2CAE2C0560C9B634596293E49" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentPeriodEndDate_1962C5B2CAE2C0560C9B634596293E49" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentTransitionReport" xlink:label="loc_dei_DocumentTransitionReport_9B3C6FDED05C6DB7A12563459629D466" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentTransitionReport_9B3C6FDED05C6DB7A12563459629D466" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityFileNumber" xlink:label="loc_dei_EntityFileNumber_A9310511FE0700D99E3D6345962AC916" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityFileNumber_A9310511FE0700D99E3D6345962AC916" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_6237ADCD1CD7F86E6BB56345962A5FBF" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityRegistrantName_6237ADCD1CD7F86E6BB56345962A5FBF" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="loc_dei_EntityIncorporationStateCountryCode_A21CDA11B16F05A2F77A6345962AEBD0" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityIncorporationStateCountryCode_A21CDA11B16F05A2F77A6345962AEBD0" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityTaxIdentificationNumber" xlink:label="loc_dei_EntityTaxIdentificationNumber_45E55FD786BEDFBF18116345962A74BF" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityTaxIdentificationNumber_45E55FD786BEDFBF18116345962A74BF" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityAddressAddressLine1" xlink:label="loc_dei_EntityAddressAddressLine1_96B75EE479416162A4AA6345962B33D5" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityAddressAddressLine1_96B75EE479416162A4AA6345962B33D5" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityAddressCityOrTown" xlink:label="loc_dei_EntityAddressCityOrTown_5A419236D64E759F94896345962BCD3B" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityAddressCityOrTown_5A419236D64E759F94896345962BCD3B" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityAddressStateOrProvince" xlink:label="loc_dei_EntityAddressStateOrProvince_6F7A675F168F215559576345962B5687" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityAddressStateOrProvince_6F7A675F168F215559576345962B5687" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityAddressPostalZipCode" xlink:label="loc_dei_EntityAddressPostalZipCode_3C9C011DA3C6A5D9F4746345962BC0B4" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityAddressPostalZipCode_3C9C011DA3C6A5D9F4746345962BC0B4" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_CityAreaCode" xlink:label="loc_dei_CityAreaCode_BDA775D46FAFC451FD666345962C0B7A" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_CityAreaCode_BDA775D46FAFC451FD666345962C0B7A" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LocalPhoneNumber" xlink:label="loc_dei_LocalPhoneNumber_D7E7AF3E5DAAFB3304BB6345962C7649" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_LocalPhoneNumber_D7E7AF3E5DAAFB3304BB6345962C7649" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_Security12bTitle" xlink:label="loc_dei_Security12bTitle_79AA26FDEFF43A892C896345962CF6A3" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_Security12bTitle_79AA26FDEFF43A892C896345962CF6A3" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_TradingSymbol" xlink:label="loc_dei_TradingSymbol_E7C7D09F07C1A2821AD56345962DA47A" xlink:type="locator"/>

<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_TradingSymbol_E7C7D09F07C1A2821AD56345962DA47A" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_SecurityExchangeName" xlink:label="loc_dei_SecurityExchangeName_CE087006E83E4C6D5B0C6345962D6ED4" xlink:type="locator"/>

<link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_SecurityExchangeName_CE087006E83E4C6D5B0C6345962D6ED4" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_AC6853ECB54B6706C38C6345962D611D" xlink:type="locator"/>

<link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_AC6853ECB54B6706C38C6345962D611D" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="loc_dei_EntityVoluntaryFilers_BC251412B3F60211A5DB6345962DC3E1" xlink:type="locator"/>

<link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityVoluntaryFilers_BC251412B3F60211A5DB6345962DC3E1" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="loc_dei_EntityCurrentReportingStatus_F733BD364D8D6A04C6A86345962D6441" xlink:type="locator"/>

<link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityCurrentReportingStatus_F733BD364D8D6A04C6A86345962D6441" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityInteractiveDataCurrent" xlink:label="loc_dei_EntityInteractiveDataCurrent_2F8EF6A56C65F442677F6345962D12A8" xlink:type="locator"/>

<link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityInteractiveDataCurrent_2F8EF6A56C65F442677F6345962D12A8" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_7F83FA39A0ED155206416345962E39CC" xlink:type="locator"/>

<link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityFilerCategory_7F83FA39A0ED155206416345962E39CC" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntitySmallBusiness" xlink:label="loc_dei_EntitySmallBusiness_7C0BCCCD0F655F77E6DB6345962E0F76" xlink:type="locator"/>

<link:definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntitySmallBusiness_7C0BCCCD0F655F77E6DB6345962E0F76" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityEmergingGrowthCompany" xlink:label="loc_dei_EntityEmergingGrowthCompany_3A083331DF2650C7BEBF6345962E328D" xlink:type="locator"/>

<link:definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityEmergingGrowthCompany_3A083331DF2650C7BEBF6345962E328D" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityShellCompany" xlink:label="loc_dei_EntityShellCompany_8DA18C4A8E01F3E088356345962FB1FB" xlink:type="locator"/>

<link:definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityShellCompany_8DA18C4A8E01F3E088356345962FB1FB" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityPublicFloat" xlink:label="loc_dei_EntityPublicFloat_DC1F65D8254DC5D8D28A6345962F6611" xlink:type="locator"/>

<link:definitionArc order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityPublicFloat_DC1F65D8254DC5D8D28A6345962F6611" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_D19AB4730A064B8555786345962FDE24" xlink:type="locator"/>

<link:definitionArc order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_D19AB4730A064B8555786345962FDE24" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_8319C6E76B1669C9D3776345962FA75D" xlink:type="locator"/>

<link:definitionArc order="28" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_EntityCentralIndexKey_8319C6E76B1669C9D3776345962FA75D" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_095185877672DCA18C0F634596341F08" xlink:type="locator"/>

<link:definitionArc order="29" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentFiscalPeriodFocus_095185877672DCA18C0F634596341F08" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_1DD9762038742917D467634596354625" xlink:type="locator"/>

<link:definitionArc order="30" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_DocumentFiscalYearFocus_1DD9762038742917D467634596354625" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_4EF3E54A6E5E47464FFF634596354144" xlink:type="locator"/>

<link:definitionArc order="31" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_CurrentFiscalYearEndDate_4EF3E54A6E5E47464FFF634596354144" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_E39FAF2CB95197B9963563459635B259" xlink:type="locator"/>

<link:definitionArc order="32" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_0CEEEB61522AE0CED3286345962817B8" xlink:to="loc_dei_AmendmentFlag_E39FAF2CB95197B9963563459635B259" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/Debt" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtCommercialPaperNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_152EE0DA1A5FD55005B4634592C6A33E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_152EE0DA1A5FD55005B4634592C6A33E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_757C0B5A8E62DF13E35E634592C6F72B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_152EE0DA1A5FD55005B4634592C6A33E" xlink:to="loc_us-gaap_CreditFacilityAxis_757C0B5A8E62DF13E35E634592C6F72B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_CDE2F7B5BBEB3A4FD244634592C765FA_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_757C0B5A8E62DF13E35E634592C6F72B" xlink:to="loc_us-gaap_CreditFacilityDomain_CDE2F7B5BBEB3A4FD244634592C765FA_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_757C0B5A8E62DF13E35E634592C6F72B" xlink:to="loc_us-gaap_CreditFacilityDomain_CDE2F7B5BBEB3A4FD244634592C765FA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_AC08DB171CC42D3803FF634592C70269" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_CDE2F7B5BBEB3A4FD244634592C765FA" xlink:to="loc_us-gaap_CommercialPaperMember_AC08DB171CC42D3803FF634592C70269" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_E97755C3EBB3A8F73E99634592C8EA41" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_152EE0DA1A5FD55005B4634592C6A33E" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_E97755C3EBB3A8F73E99634592C8EA41" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_6D92E1A7948012EE2002634592C860DD_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_E97755C3EBB3A8F73E99634592C8EA41" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_6D92E1A7948012EE2002634592C860DD_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_6D92E1A7948012EE2002634592C860DD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_E97755C3EBB3A8F73E99634592C8EA41" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_6D92E1A7948012EE2002634592C860DD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_08CB1A17B2489059B82E634592C8BF73" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_6D92E1A7948012EE2002634592C860DD" xlink:to="loc_us-gaap_SubsequentEventMember_08CB1A17B2489059B82E634592C8BF73" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_81308F10E99629DB078A634592C94803" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_81308F10E99629DB078A634592C94803" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommercialPaper" xlink:label="loc_us-gaap_CommercialPaper_C663FB9CE78F69CD38BA634592C92205" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:to="loc_us-gaap_CommercialPaper_C663FB9CE78F69CD38BA634592C92205" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm_E620C4E590858DE781C9634592C92017" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:to="loc_us-gaap_DebtInstrumentTerm_E620C4E590858DE781C9634592C92017" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShortTermDebtWeightedAverageInterestRate" xlink:label="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_844DE80C8AC035227B2E634592CA48BB" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_145D12ABDBCF9ECB2A8B634592C8D65C" xlink:to="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_844DE80C8AC035227B2E634592CA48BB" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtCreditFacilityNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_62556C3B6FEAB9C0F361634592BA2E4C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_62556C3B6FEAB9C0F361634592BA2E4C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_C8029E1E9E2FA4FD4547634592BA38DC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_62556C3B6FEAB9C0F361634592BA2E4C" xlink:to="loc_us-gaap_DebtInstrumentAxis_C8029E1E9E2FA4FD4547634592BA38DC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_C8029E1E9E2FA4FD4547634592BA38DC" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_C8029E1E9E2FA4FD4547634592BA38DC" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSCreditFacilityMember" xlink:label="loc_viac_CBSCreditFacilityMember_B647C2138C181D8E1015634592BB69E8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52" xlink:to="loc_viac_CBSCreditFacilityMember_B647C2138C181D8E1015634592BB69E8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomCreditFacilityMember" xlink:label="loc_viac_ViacomCreditFacilityMember_43880296BAFD158F4FC9634592BBC1BC" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52" xlink:to="loc_viac_ViacomCreditFacilityMember_43880296BAFD158F4FC9634592BBC1BC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomCBSCreditFacilityMember" xlink:label="loc_viac_ViacomCBSCreditFacilityMember_B29F0CC06ED6B8F98CC5634592BBBAF2" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_9338E157286870DD2CA0634592BA5F52" xlink:to="loc_viac_ViacomCBSCreditFacilityMember_B29F0CC06ED6B8F98CC5634592BBBAF2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_95C5F81DBE567D4875BB634592BC542B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_62556C3B6FEAB9C0F361634592BA2E4C" xlink:to="loc_us-gaap_CreditFacilityAxis_95C5F81DBE567D4875BB634592BC542B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_B0C51C071E27255687D7634592BCE128_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_95C5F81DBE567D4875BB634592BC542B" xlink:to="loc_us-gaap_CreditFacilityDomain_B0C51C071E27255687D7634592BCE128_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_B0C51C071E27255687D7634592BCE128" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_95C5F81DBE567D4875BB634592BC542B" xlink:to="loc_us-gaap_CreditFacilityDomain_B0C51C071E27255687D7634592BCE128" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_AB24B0466C12E9191E30634592BC6CE4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_B0C51C071E27255687D7634592BCE128" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_AB24B0466C12E9191E30634592BC6CE4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_7E12DB12F5E0B4C938C8634592BCE9B5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_62556C3B6FEAB9C0F361634592BA2E4C" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_7E12DB12F5E0B4C938C8634592BCE9B5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_43100B4A4247685B1B83634592BD73CD_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7E12DB12F5E0B4C938C8634592BCE9B5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_43100B4A4247685B1B83634592BD73CD_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_43100B4A4247685B1B83634592BD73CD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7E12DB12F5E0B4C938C8634592BCE9B5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_43100B4A4247685B1B83634592BD73CD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_C3C5BB4181AB6B587E25634592BDCE02" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_43100B4A4247685B1B83634592BD73CD" xlink:to="loc_us-gaap_SubsequentEventMember_C3C5BB4181AB6B587E25634592BDCE02" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5EDCD75CF711A49314FC634592BE0D86" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5EDCD75CF711A49314FC634592BE0D86" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_3C43AAEA0D32963A7BE4634592BEAF1C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_us-gaap_LineOfCredit_3C43AAEA0D32963A7BE4634592BEAF1C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_375610B2B7CC573649CC634592BE58F0" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_375610B2B7CC573649CC634592BE58F0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatio" xlink:label="loc_viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatio_F1156300B64B90180C98634592BE4516" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatio_F1156300B64B90180C98634592BE4516" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatioAccordionFeatureIncrease" xlink:label="loc_viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatioAccordionFeatureIncrease_C49E7139931782D6056D634592BFD35B" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_viac_LineofCreditFacilityCovenantMaximumConsolidatedLeverageRatioAccordionFeatureIncrease_C49E7139931782D6056D634592BFD35B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DebtInstrumentPeriodforConsolidatedEBITDA" xlink:label="loc_viac_DebtInstrumentPeriodforConsolidatedEBITDA_3F752CEF1556A20C8013634592BF7E0B" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_957D816BED0BF46C4B94634592BDB56E" xlink:to="loc_viac_DebtInstrumentPeriodforConsolidatedEBITDA_3F752CEF1556A20C8013634592BF7E0B" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtMaturitiesOfLongTermDebtDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_2680D627270A34297A11634592DC81F3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_2680D627270A34297A11634592DC81F3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_8DAA854E4DFBE3DAD260634592DC785B_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2680D627270A34297A11634592DC81F3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_8DAA854E4DFBE3DAD260634592DC785B_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2680D627270A34297A11634592DC81F3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_8DAA854E4DFBE3DAD260634592DC785B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JuniorDebenturesAndSeniorNotesMember" xlink:label="loc_viac_JuniorDebenturesAndSeniorNotesMember_4A3BA77EB97CD33C5AAB634592DC7DB4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_8DAA854E4DFBE3DAD260634592DC785B" xlink:to="loc_viac_JuniorDebenturesAndSeniorNotesMember_4A3BA77EB97CD33C5AAB634592DC7DB4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_5560711141B79F0789FD634592DDD20F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_8DAA854E4DFBE3DAD260634592DC785B" xlink:to="loc_us-gaap_SeniorNotesMember_5560711141B79F0789FD634592DDD20F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_317E17E39140BA900F39634592DD093A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:to="loc_us-gaap_DebtInstrumentAxis_317E17E39140BA900F39634592DD093A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_317E17E39140BA900F39634592DD093A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_317E17E39140BA900F39634592DD093A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2029Member" xlink:label="loc_viac_SeniorNotesDue2029Member_20C8DB7B2B888316CDDD634592DE0E02" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_SeniorNotesDue2029Member_20C8DB7B2B888316CDDD634592DE0E02" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DebtDueAugust2019Member" xlink:label="loc_viac_DebtDueAugust2019Member_D97CF81BCCD05CB832A1634592DE701A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_DebtDueAugust2019Member_D97CF81BCCD05CB832A1634592DE701A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesSept2019Member" xlink:label="loc_viac_SeniorNotesSept2019Member_EACB1AE8E1FD63896012634592DF0135" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_SeniorNotesSept2019Member_EACB1AE8E1FD63896012634592DF0135" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDec2019Member" xlink:label="loc_viac_SeniorNotesDec2019Member_01C8679AFF56943D0D1B634592DF23B9" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_SeniorNotesDec2019Member_01C8679AFF56943D0D1B634592DF23B9" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember" xlink:label="loc_viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember_98DABF2655CC7907DC04634592DF3770" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember_98DABF2655CC7907DC04634592DF3770" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember" xlink:label="loc_viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember_68F54FF888CB1DCD81B7634592DF0A31" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember_68F54FF888CB1DCD81B7634592DF0A31" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesFebruary2022Member" xlink:label="loc_viac_SeniorNotesFebruary2022Member_385388DA60987FB7248B634592DFAE6D" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_SeniorNotesFebruary2022Member_385388DA60987FB7248B634592DFAE6D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesdueOctober2026Member" xlink:label="loc_viac_SeniorNotesdueOctober2026Member_308B1CB8FB278B7729F8634592E01895" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_709C0927E8B0920603BF634592DD1D3C" xlink:to="loc_viac_SeniorNotesdueOctober2026Member_308B1CB8FB278B7729F8634592E01895" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_CF86DB2A7D051DD476DE634592E08B52" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:to="loc_us-gaap_VariableRateAxis_CF86DB2A7D051DD476DE634592E08B52" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_966FC63262D1CAA54635634592E07438_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_CF86DB2A7D051DD476DE634592E08B52" xlink:to="loc_us-gaap_VariableRateDomain_966FC63262D1CAA54635634592E07438_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_CF86DB2A7D051DD476DE634592E08B52" xlink:to="loc_us-gaap_VariableRateDomain_966FC63262D1CAA54635634592E07438" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_63FA983108A74BDC89BC634592E0575B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_966FC63262D1CAA54635634592E07438" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_63FA983108A74BDC89BC634592E0575B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_54F3933D38393B823775634592E1F4CD" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_7079FCEA6CBA7AEBB25B634592DB8340" xlink:to="loc_srt_RangeAxis_54F3933D38393B823775634592E1F4CD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_F3B852488B39E2304E2B634592E1072A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_54F3933D38393B823775634592E1F4CD" xlink:to="loc_srt_RangeMember_F3B852488B39E2304E2B634592E1072A_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_F3B852488B39E2304E2B634592E1072A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_54F3933D38393B823775634592E1F4CD" xlink:to="loc_srt_RangeMember_F3B852488B39E2304E2B634592E1072A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_43E7C55393A41BB96D89634592E16551" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_F3B852488B39E2304E2B634592E1072A" xlink:to="loc_srt_MaximumMember_43E7C55393A41BB96D89634592E16551" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_304E7959745CF74C2AF4634592E2C554" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_304E7959745CF74C2AF4634592E2C554" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9FC8EB10DFEAD7FA5B98634592E25434" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9FC8EB10DFEAD7FA5B98634592E25434" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DebtInstrumentInterestRatePotentialChange" xlink:label="loc_viac_DebtInstrumentInterestRatePotentialChange_5CE921B176417934BB3F634592E39C04" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_viac_DebtInstrumentInterestRatePotentialChange_5CE921B176417934BB3F634592E39C04" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RepaymentsOfDebt" xlink:label="loc_us-gaap_RepaymentsOfDebt_2DA0ADD2CBCA9B171EF9634592E3AAFD" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_RepaymentsOfDebt_2DA0ADD2CBCA9B171EF9634592E3AAFD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_DEABF5E6EC3C1FD708C1634592E3CBDD" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_DEABF5E6EC3C1FD708C1634592E3CBDD" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DebtInstrumentRedemptionAmount" xlink:label="loc_viac_DebtInstrumentRedemptionAmount_0E946B454E06E67AFD9D634592E37E76" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_viac_DebtInstrumentRedemptionAmount_0E946B454E06E67AFD9D634592E37E76" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_AB23807A02689D409B43634592E36A29" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_AB23807A02689D409B43634592E36A29" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ExtinguishmentOfDebtGainLossNetOfTax" xlink:label="loc_us-gaap_ExtinguishmentOfDebtGainLossNetOfTax_A7F8EAD6D453ADFA8B4A634592E3B6FA" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_ExtinguishmentOfDebtGainLossNetOfTax_A7F8EAD6D453ADFA8B4A634592E3B6FA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5BD7789B8B7EF5AEB1EB634592E40F5B" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5BD7789B8B7EF5AEB1EB634592E40F5B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_361A8F91518AB007CF39634592E4DA55" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_762BACFDE2F0F6A77004634592E2E5CB" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_361A8F91518AB007CF39634592E4DA55" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtScheduleOfDebtDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_8F913A2424632C240008648B0EE8444F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DebtInstrumentTable_8F913A2424632C240008648B0EE8444F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_E49B364F72E45EE2504E648B0EE9AA1B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8F913A2424632C240008648B0EE8444F" xlink:to="loc_us-gaap_DebtInstrumentAxis_E49B364F72E45EE2504E648B0EE9AA1B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_E49B364F72E45EE2504E648B0EE9AA1B" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_E49B364F72E45EE2504E648B0EE9AA1B" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2019BMember" xlink:label="loc_viac_SeniorNotesDue2019BMember_75FB3FEEFEF481C3D1E5648B0EE9A1BC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2019BMember_75FB3FEEFEF481C3D1E5648B0EE9A1BC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesSept2019Member" xlink:label="loc_viac_SeniorNotesSept2019Member_E6A0A89F24208613C85D648B0EE975E5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesSept2019Member_E6A0A89F24208613C85D648B0EE975E5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDec2019Member" xlink:label="loc_viac_SeniorNotesDec2019Member_2EBC305ED1B6B613EA24648B0EEA34A6" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDec2019Member_2EBC305ED1B6B613EA24648B0EEA34A6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotes2021Member" xlink:label="loc_viac_SeniorNotes2021Member_12F8C9FF1E2BCAFA3FF5648B0EEA984B" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotes2021Member_12F8C9FF1E2BCAFA3FF5648B0EEA984B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesMar2021Member" xlink:label="loc_viac_SeniorNotesMar2021Member_18E0A6F835E0EB271728648B0EEA2202" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesMar2021Member_18E0A6F835E0EB271728648B0EEA2202" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDec2021Member" xlink:label="loc_viac_SeniorNotesDec2021Member_B93455E84E58FF687095648B0EEC78CD" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDec2021Member_B93455E84E58FF687095648B0EEC78CD" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotes2022Member" xlink:label="loc_viac_SeniorNotes2022Member_884E10057A515920D67C648B0EEC22E8" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotes2022Member_884E10057A515920D67C648B0EEC22E8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesFebruary2022Member" xlink:label="loc_viac_SeniorNotesFebruary2022Member_4E7451645D325249C57B648B0EECBB54" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesFebruary2022Member_4E7451645D325249C57B648B0EECBB54" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesJune2022Member" xlink:label="loc_viac_SeniorNotesJune2022Member_445723533D6588A33E12648B0EEDEA4C" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesJune2022Member_445723533D6588A33E12648B0EEDEA4C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_Debentures2023Member" xlink:label="loc_viac_Debentures2023Member_2976846499961CA711D2648B0EED75E8" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_Debentures2023Member_2976846499961CA711D2648B0EED75E8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2023Member" xlink:label="loc_viac_SeniorNotesDue2023Member_248DD172B4501C6B40E6648B0EED8090" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2023Member_248DD172B4501C6B40E6648B0EED8090" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue20232.90PercentMember" xlink:label="loc_viac_SeniorNotesDue20232.90PercentMember_9F0F3FAEC440722F0049648B0EED3B73" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue20232.90PercentMember_9F0F3FAEC440722F0049648B0EED3B73" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue20232.50PercentMember" xlink:label="loc_viac_SeniorNotesDue20232.50PercentMember_CAAB610492AF3F0E9C71648B0EED11E2" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue20232.50PercentMember_CAAB610492AF3F0E9C71648B0EED11E2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesMar2023Member" xlink:label="loc_viac_SeniorNotesMar2023Member_9079252D503B92F9D32C648B0EED805F" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesMar2023Member_9079252D503B92F9D32C648B0EED805F" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesSep2023Member" xlink:label="loc_viac_SeniorNotesSep2023Member_F7D277F2F58AC4CDD415648B0EEE147A" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesSep2023Member_F7D277F2F58AC4CDD415648B0EEE147A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2024Member" xlink:label="loc_viac_SeniorNotesDue2024Member_8729249908034D9B450B648B0EEEBC7B" xlink:type="locator"/>

<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2024Member_8729249908034D9B450B648B0EEEBC7B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesApr2024Member" xlink:label="loc_viac_SeniorNotesApr2024Member_22786DFEF7893ABC1FB3648B0EEE4B79" xlink:type="locator"/>

<link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesApr2024Member_22786DFEF7893ABC1FB3648B0EEE4B79" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2025Member" xlink:label="loc_viac_SeniorNotesDue2025Member_73A43EF9F2667E0A4471648B0EEE0120" xlink:type="locator"/>

<link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2025Member_73A43EF9F2667E0A4471648B0EEE0120" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2026Member" xlink:label="loc_viac_SeniorNotesDue2026Member_59E97D17F25FFC4A4B0E648B0EEE8E17" xlink:type="locator"/>

<link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2026Member_59E97D17F25FFC4A4B0E648B0EEE8E17" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesdueOctober2026Member" xlink:label="loc_viac_SeniorNotesdueOctober2026Member_FC4CC3E3557799E23592648B0EEE6E9D" xlink:type="locator"/>

<link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesdueOctober2026Member_FC4CC3E3557799E23592648B0EEE6E9D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2027Member" xlink:label="loc_viac_SeniorNotesDue2027Member_AE9A5820AC855F047525648B0EEE9C5A" xlink:type="locator"/>

<link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2027Member_AE9A5820AC855F047525648B0EEE9C5A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2028Member" xlink:label="loc_viac_SeniorNotesDue2028Member_29DCE52B47A15922D40B648B0EEFC313" xlink:type="locator"/>

<link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2028Member_29DCE52B47A15922D40B648B0EEFC313" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue20283.70PercentMember" xlink:label="loc_viac_SeniorNotesDue20283.70PercentMember_9F781AF84717F713B096648B0EEFCE0C" xlink:type="locator"/>

<link:definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue20283.70PercentMember_9F781AF84717F713B096648B0EEFCE0C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2029Member" xlink:label="loc_viac_SeniorNotesDue2029Member_94B2416E7BE3CEF689B6648B0EEFA470" xlink:type="locator"/>

<link:definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2029Member_94B2416E7BE3CEF689B6648B0EEFA470" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesDue2030Member" xlink:label="loc_viac_SeniorDebenturesDue2030Member_C8C90FB7E82B28E7C442648B0EEF216B" xlink:type="locator"/>

<link:definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesDue2030Member_C8C90FB7E82B28E7C442648B0EEF216B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebentures2033Member" xlink:label="loc_viac_SeniorDebentures2033Member_C19638C93C9C0971FAEF648B0EEF40F6" xlink:type="locator"/>

<link:definitionArc order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebentures2033Member_C19638C93C9C0971FAEF648B0EEF40F6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesDecember2034Member" xlink:label="loc_viac_SeniorDebenturesDecember2034Member_72B325FB1E4F439789A1648B0EEFECDA" xlink:type="locator"/>

<link:definitionArc order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesDecember2034Member_72B325FB1E4F439789A1648B0EEFECDA" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesApr2036Member" xlink:label="loc_viac_SeniorDebenturesApr2036Member_3F1D1A2A17A10938F787648B0EEFF86E" xlink:type="locator"/>

<link:definitionArc order="28" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesApr2036Member_3F1D1A2A17A10938F787648B0EEFF86E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesOct2037Member" xlink:label="loc_viac_SeniorDebenturesOct2037Member_0EF6B9F031D95F5E65CA648B0EF0F628" xlink:type="locator"/>

<link:definitionArc order="29" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesOct2037Member_0EF6B9F031D95F5E65CA648B0EF0F628" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotes2040Member" xlink:label="loc_viac_SeniorNotes2040Member_2522A362F6D70331ED38648B0EF0F921" xlink:type="locator"/>

<link:definitionArc order="30" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotes2040Member_2522A362F6D70331ED38648B0EF0F921" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotes2042Member" xlink:label="loc_viac_SeniorNotes2042Member_1A3957146F48344DAD75648B0EF02332" xlink:type="locator"/>

<link:definitionArc order="31" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotes2042Member_1A3957146F48344DAD75648B0EF02332" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesFeb2042Member" xlink:label="loc_viac_SeniorDebenturesFeb2042Member_2C9303A9E74B77436995648B0EF00E00" xlink:type="locator"/>

<link:definitionArc order="32" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesFeb2042Member_2C9303A9E74B77436995648B0EF00E00" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesMar2043Member" xlink:label="loc_viac_SeniorDebenturesMar2043Member_832E07A82E2D5FFE2AE9648B0EF0EFCC" xlink:type="locator"/>

<link:definitionArc order="33" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesMar2043Member_832E07A82E2D5FFE2AE9648B0EF0EFCC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesJune2043Member" xlink:label="loc_viac_SeniorDebenturesJune2043Member_08FE2836998EB0969EE5648B0EF19846" xlink:type="locator"/>

<link:definitionArc order="34" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesJune2043Member_08FE2836998EB0969EE5648B0EF19846" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesSep2043Member" xlink:label="loc_viac_SeniorDebenturesSep2043Member_6788ABDCD92D62126FC0648B0EF10797" xlink:type="locator"/>

<link:definitionArc order="35" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesSep2043Member_6788ABDCD92D62126FC0648B0EF10797" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2044Member" xlink:label="loc_viac_SeniorNotesDue2044Member_E63154BCD7A2C85FA009648B0EF14FDA" xlink:type="locator"/>

<link:definitionArc order="36" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2044Member_E63154BCD7A2C85FA009648B0EF14FDA" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorDebenturesApr2044Member" xlink:label="loc_viac_SeniorDebenturesApr2044Member_FD73D4FD053068D7039C648B0EF15219" xlink:type="locator"/>

<link:definitionArc order="37" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorDebenturesApr2044Member_FD73D4FD053068D7039C648B0EF15219" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SeniorNotesDue2045Member" xlink:label="loc_viac_SeniorNotesDue2045Member_C97E06A35294B07F02EB648B0EF1B3B0" xlink:type="locator"/>

<link:definitionArc order="38" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_SeniorNotesDue2045Member_C97E06A35294B07F02EB648B0EF1B3B0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember" xlink:label="loc_viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember_4D7888190284C68D9A9B648B0EF1D207" xlink:type="locator"/>

<link:definitionArc order="39" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_JuniorSubordinatedDebenturesFebruary20575YearHybridMember_4D7888190284C68D9A9B648B0EF1D207" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember" xlink:label="loc_viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember_006E46812AF17C18AECA648B0EF2D21A" xlink:type="locator"/>

<link:definitionArc order="40" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_471BE6DD14F5E1A0881E648B0EE9D022" xlink:to="loc_viac_JuniorSubordinatedDebentureFebruary205710YearHybridMember_006E46812AF17C18AECA648B0EF2D21A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommercialPaper" xlink:label="loc_us-gaap_CommercialPaper_E80940521FE328C29580648B0EF207BF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_CommercialPaper_E80940521FE328C29580648B0EF207BF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SeniorNotes" xlink:label="loc_us-gaap_SeniorNotes_CEC216702BD93F95BD9E648B0EF254AE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_SeniorNotes_CEC216702BD93F95BD9E648B0EF254AE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_JuniorSubordinatedNotes" xlink:label="loc_us-gaap_JuniorSubordinatedNotes_AED1CAAEB1D36837CD53648B0EF27900" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_JuniorSubordinatedNotes_AED1CAAEB1D36837CD53648B0EF27900" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_BC4D168E7C2CF63FE6E2648B0EF34A84" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_BC4D168E7C2CF63FE6E2648B0EF34A84" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiability" xlink:label="loc_us-gaap_FinanceLeaseLiability_64A038410573FFD29F7E648B0EF3DBF4" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_FinanceLeaseLiability_64A038410573FFD29F7E648B0EF3DBF4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" xlink:label="loc_us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments_37D9447B73B23D16D6F3648B0EF3551E" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments_37D9447B73B23D16D6F3648B0EF3551E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_F1FE980774428FCBD638648B0EF3B4D8" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_F1FE980774428FCBD638648B0EF3B4D8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_2DC5873E3DEFD394A710648B0EF38291" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_2DC5873E3DEFD394A710648B0EF38291" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_4F106AD3A8044E7D1591648B0EF41A94" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_4F106AD3A8044E7D1591648B0EF41A94" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_D99D81ED3586505081CD648B0EF47C94" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_D99D81ED3586505081CD648B0EF47C94" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_BBDAE9512CFFD488117A648B0EF4C80F" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_BBDAE9512CFFD488117A648B0EF4C80F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredGainLossOnDiscontinuationOfFairValueHedge" xlink:label="loc_us-gaap_DeferredGainLossOnDiscontinuationOfFairValueHedge_CE23BB3D5E61241B8F7C648B0EF49375" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DeferredGainLossOnDiscontinuationOfFairValueHedge_CE23BB3D5E61241B8F7C648B0EF49375" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_DAAA553703051AC173F2648B0EF48AE7" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A694D6C4B20D57E71C55648B0EF28432" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_DAAA553703051AC173F2648B0EF48AE7" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DebtTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DiscontinuedOperations" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DiscontinuedOperationsNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_F6DC33FCF965020AED11636D139C18BB" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B8491D2EAF0DA6EBE7CE636D1398205D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_F6DC33FCF965020AED11636D139C18BB" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B8491D2EAF0DA6EBE7CE636D1398205D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_47DF349FAE315280A866636D1398AC49" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B8491D2EAF0DA6EBE7CE636D1398205D" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_47DF349FAE315280A866636D1398AC49" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_D0A23BD83556BE9AB532636D1399CFF8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_47DF349FAE315280A866636D1398AC49" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_D0A23BD83556BE9AB532636D1399CFF8_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_47DF349FAE315280A866636D1398AC49" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_D0A23BD83556BE9AB532636D1399CFF8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSRadioMember" xlink:label="loc_viac_CBSRadioMember_82D61DCA64209F5F3AB8636D13995E0F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_D0A23BD83556BE9AB532636D1399CFF8" xlink:to="loc_viac_CBSRadioMember_82D61DCA64209F5F3AB8636D13995E0F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_18AD399F537DA1F4C95F636D1399F0E4" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B8491D2EAF0DA6EBE7CE636D1398205D" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_18AD399F537DA1F4C95F636D1399F0E4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_335F83C46BB303C5ECC4636D139A2C3A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_18AD399F537DA1F4C95F636D1399F0E4" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_335F83C46BB303C5ECC4636D139A2C3A_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_18AD399F537DA1F4C95F636D1399F0E4" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_335F83C46BB303C5ECC4636D139A2C3A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_C256E2C92A7E16DEC45D636D139A13DD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_335F83C46BB303C5ECC4636D139A2C3A" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_C256E2C92A7E16DEC45D636D139A13DD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_DF46A4E05E2FFAEEC074636D139AC5D8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B8491D2EAF0DA6EBE7CE636D1398205D" xlink:to="loc_us-gaap_StatementClassOfStockAxis_DF46A4E05E2FFAEEC074636D139AC5D8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_DF46A4E05E2FFAEEC074636D139AC5D8" xlink:to="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_DF46A4E05E2FFAEEC074636D139AC5D8" xlink:to="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_F6105E51506C8A47FE82636D139BE3DF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE" xlink:to="loc_us-gaap_CommonClassBMember_F6105E51506C8A47FE82636D139BE3DF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_F58201F317C45BAB9584636D139B77F4" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2DC8ABDC6C52D5C63947636D139A8FFE" xlink:to="loc_us-gaap_CommonStockMember_F58201F317C45BAB9584636D139B77F4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationSharesReceivedinExchangeOffer" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationSharesReceivedinExchangeOffer_D9AA21D8F50C78515604636D139CAB23" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_F6DC33FCF965020AED11636D139C18BB" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationSharesReceivedinExchangeOffer_D9AA21D8F50C78515604636D139CAB23" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationSharesExchangedinExchangeOffer" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationSharesExchangedinExchangeOffer_6AC7981DEB606EAF2993636D139CC06F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_F6DC33FCF965020AED11636D139C18BB" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationSharesExchangedinExchangeOffer_6AC7981DEB606EAF2993636D139CC06F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DiscontinuedOperationsNetEarningsLossDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FBD1F692231FAD9F16DB63458F4E5FE3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FBD1F692231FAD9F16DB63458F4E5FE3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_57ED207462CF60D8F16463458F4E755A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FBD1F692231FAD9F16DB63458F4E5FE3" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_57ED207462CF60D8F16463458F4E755A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_4F6BC8CD30702C0D30E163458F4F826E_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_57ED207462CF60D8F16463458F4E755A" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_4F6BC8CD30702C0D30E163458F4F826E_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_4F6BC8CD30702C0D30E163458F4F826E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_57ED207462CF60D8F16463458F4E755A" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_4F6BC8CD30702C0D30E163458F4F826E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_CCE57B63DECCFBA6573663458F4F7403" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_4F6BC8CD30702C0D30E163458F4F826E" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_CCE57B63DECCFBA6573663458F4F7403" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_2ACC9FA48FF70712CD2363458F4F8842" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FBD1F692231FAD9F16DB63458F4E5FE3" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_2ACC9FA48FF70712CD2363458F4F8842" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_2ACC9FA48FF70712CD2363458F4F8842" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_2ACC9FA48FF70712CD2363458F4F8842" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSRadioMember" xlink:label="loc_viac_CBSRadioMember_0ADB5429E1EECAA8BDA463458F50A06E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580" xlink:to="loc_viac_CBSRadioMember_0ADB5429E1EECAA8BDA463458F50A06E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PreviousDisposedBusinessMember" xlink:label="loc_viac_PreviousDisposedBusinessMember_FC0B2D0069E8363692DC63458F50B58D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C5B58AFF7BDE4DD0CFDD63458F4F5580" xlink:to="loc_viac_PreviousDisposedBusinessMember_FC0B2D0069E8363692DC63458F50B58D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_D1D702BA1DAD1FB6D0DA63458F51292C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_D1D702BA1DAD1FB6D0DA63458F51292C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_C5F107D69B24A5D65CB463458F515679" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_C5F107D69B24A5D65CB463458F515679" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense_865E7543AC29552D6F6463458F5128DE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense_865E7543AC29552D6F6463458F5128DE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationMarketValueAdjustment" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationMarketValueAdjustment_A4F6E945053CED5193AF63458F527460" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationMarketValueAdjustment_A4F6E945053CED5193AF63458F527460" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationRestructuringCharges" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationRestructuringCharges_884F5ED0D1C72CFF698863458F525615" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationRestructuringCharges_884F5ED0D1C72CFF698863458F525615" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationCostsandExpense" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostsandExpense_A6ADBAB5FA7DA1537BEA63458F57A7D9" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostandExpensesAbstract_4ADE5F2A6DC32B0EF9D663458F517B9B" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationCostsandExpense_A6ADBAB5FA7DA1537BEA63458F57A7D9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss_0B59F5450340F74BE17563458F58A5B7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss_0B59F5450340F74BE17563458F58A5B7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense_81DCE36EBB9217C04E8063458F5897A0" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense_81DCE36EBB9217C04E8063458F5897A0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:label="loc_viac_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense_EB26A9F290FDE0D73DC363458F58B81B" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_viac_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense_EB26A9F290FDE0D73DC363458F58B81B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax" xlink:label="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax_3A3F1B12707E2B16476E63458F58AB20" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax_3A3F1B12707E2B16476E63458F58AB20" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod" xlink:label="loc_us-gaap_DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod_970C41FA7DAD9D17FF4863458F59857A" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod_970C41FA7DAD9D17FF4863458F59857A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:label="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_6A4A1EA8F819A3A4AB7863458F599051" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_6A4A1EA8F819A3A4AB7863458F599051" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax" xlink:label="loc_us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_522A87DE5BDF54F7CFE363458F5953DD" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_522A87DE5BDF54F7CFE363458F5953DD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:label="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_67B448BA3EC6F427787C63458F5989E6" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_67B448BA3EC6F427787C63458F5989E6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:label="loc_us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax_23AB09FC74648747571863458F592CE0" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax_23AB09FC74648747571863458F592CE0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:label="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_32A83B237FF7ADE6D2AC63458F5A4938" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_D3C6FE70E674C73BCEE063458F50A5CD" xlink:to="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_32A83B237FF7ADE6D2AC63458F5A4938" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/DiscontinuedOperationsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FairValueMeasurements" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FairValueMeasurementsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8B5FE5596A1FF13F8E356345922D5821" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D7C13C9F85E817C5812B6345922B7EEA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8B5FE5596A1FF13F8E356345922D5821" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D7C13C9F85E817C5812B6345922B7EEA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_568DAD52AA4E6F70538F6345922CFD53" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D7C13C9F85E817C5812B6345922B7EEA" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_568DAD52AA4E6F70538F6345922CFD53" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_568DAD52AA4E6F70538F6345922CFD53" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_568DAD52AA4E6F70538F6345922CFD53" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_E767ECCF56A7C40EB8256345922CED47" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_E767ECCF56A7C40EB8256345922CED47" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_3BF89F30252C5F468B5F6345922D9662" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_3BF89F30252C5F468B5F6345922D9662" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_0C12B9FB1072321944016345922D6BA8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4DE84F2F462234B2175D6345922C3188" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_0C12B9FB1072321944016345922D6BA8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_D4751A9757EB797D1DE36345922DAF3C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8B5FE5596A1FF13F8E356345922D5821" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_D4751A9757EB797D1DE36345922DAF3C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketableSecurities" xlink:label="loc_us-gaap_MarketableSecurities_801AEFE40C86FB55E19D6345922ECB47" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_D4751A9757EB797D1DE36345922DAF3C" xlink:to="loc_us-gaap_MarketableSecurities_801AEFE40C86FB55E19D6345922ECB47" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignCurrencyContractAssetFairValueDisclosure" xlink:label="loc_us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_DAE842D8DCE98AAF6EA16345922E40CA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_D4751A9757EB797D1DE36345922DAF3C" xlink:to="loc_us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_DAE842D8DCE98AAF6EA16345922E40CA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_27789D6BBC8B57F433CC6345922FC2A2" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_D4751A9757EB797D1DE36345922DAF3C" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_27789D6BBC8B57F433CC6345922FC2A2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9738AE06F258FBB618076345922F61E7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8B5FE5596A1FF13F8E356345922D5821" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9738AE06F258FBB618076345922F61E7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent" xlink:label="loc_us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent_2ADAF2D2967783E1F5776345922FA0BA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9738AE06F258FBB618076345922F61E7" xlink:to="loc_us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent_2ADAF2D2967783E1F5776345922FA0BA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure" xlink:label="loc_us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure_9AA2A415FC89795955916345922FD09A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9738AE06F258FBB618076345922F61E7" xlink:to="loc_us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure_9AA2A415FC89795955916345922FD09A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_460935C1769E4C415AD4634592306286" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9738AE06F258FBB618076345922F61E7" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_460935C1769E4C415AD4634592306286" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FairValueMeasurementsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FinancialInstruments" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FinancialInstrumentsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_29E8BFCAA36E4833D67B6345924417AC" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_65CD9E3E65A3738C677163459240581C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_29E8BFCAA36E4833D67B6345924417AC" xlink:to="loc_us-gaap_DerivativeTable_65CD9E3E65A3738C677163459240581C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_3AF8A4D25397E389A3CE634592417AF1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_65CD9E3E65A3738C677163459240581C" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_3AF8A4D25397E389A3CE634592417AF1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_950D5A2D1B61C6B20E1D634592411BE7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_3AF8A4D25397E389A3CE634592417AF1" xlink:to="loc_us-gaap_HedgingRelationshipDomain_950D5A2D1B61C6B20E1D634592411BE7_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_3AF8A4D25397E389A3CE634592417AF1" xlink:to="loc_us-gaap_HedgingRelationshipDomain_950D5A2D1B61C6B20E1D634592411BE7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_F87E1EAE8B1073C8403B634592420BE8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_950D5A2D1B61C6B20E1D634592411BE7" xlink:to="loc_us-gaap_CashFlowHedgingMember_F87E1EAE8B1073C8403B634592420BE8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_111AF82B8CF766ED1AEA6345924215C5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_65CD9E3E65A3738C677163459240581C" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_111AF82B8CF766ED1AEA6345924215C5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01FE1CC596318629D5216345924250B6_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_111AF82B8CF766ED1AEA6345924215C5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01FE1CC596318629D5216345924250B6_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_111AF82B8CF766ED1AEA6345924215C5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01FE1CC596318629D5216345924250B6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_9717978A11950A7B203B63459242EC1E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01FE1CC596318629D5216345924250B6" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_9717978A11950A7B203B63459242EC1E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_0BEDCE0F678A16E8D8D563459243B17F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01FE1CC596318629D5216345924250B6" xlink:to="loc_us-gaap_ForeignExchangeContractMember_0BEDCE0F678A16E8D8D563459243B17F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_6C0A7BE1DB003652EC4B6345924354A8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_65CD9E3E65A3738C677163459240581C" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_6C0A7BE1DB003652EC4B6345924354A8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_6C0A7BE1DB003652EC4B6345924354A8" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_6C0A7BE1DB003652EC4B6345924354A8" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FutureProductionCostsMember" xlink:label="loc_viac_FutureProductionCostsMember_52ECA2E17498B884E116634592440885" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB" xlink:to="loc_viac_FutureProductionCostsMember_52ECA2E17498B884E116634592440885" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherForeignCurrencyMember" xlink:label="loc_viac_OtherForeignCurrencyMember_517C89F08604A86191E263459244BD4C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_854E2E659D570E4372716345924367CB" xlink:to="loc_viac_OtherForeignCurrencyMember_517C89F08604A86191E263459244BD4C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeTermOfContract" xlink:label="loc_us-gaap_DerivativeTermOfContract_B9F4DCCACF9C0C5E36AB63459244CA21" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_29E8BFCAA36E4833D67B6345924417AC" xlink:to="loc_us-gaap_DerivativeTermOfContract_B9F4DCCACF9C0C5E36AB63459244CA21" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeNotionalAmount" xlink:label="loc_us-gaap_DerivativeNotionalAmount_DCE26DCA8F82F7BF6A62634592445F6E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_29E8BFCAA36E4833D67B6345924417AC" xlink:to="loc_us-gaap_DerivativeNotionalAmount_DCE26DCA8F82F7BF6A62634592445F6E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_12F5B1090EB641EB249363459245DB31" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_29E8BFCAA36E4833D67B6345924417AC" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_12F5B1090EB641EB249363459245DB31" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/FinancialInstrumentsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssets" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsAmortizationExpenseDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsGoodwillDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_D34EFE0D78A7662167E0634593DC4077" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_796AB62D5CD6043380F7634593D93EF5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_D34EFE0D78A7662167E0634593DC4077" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_796AB62D5CD6043380F7634593D93EF5" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_BCB7B3EB3EB69D22D591634593D991B3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_796AB62D5CD6043380F7634593D93EF5" xlink:to="loc_srt_ConsolidationItemsAxis_BCB7B3EB3EB69D22D591634593D991B3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_EB9EF1D8F85E9CB5164F634593D944CB_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_BCB7B3EB3EB69D22D591634593D991B3" xlink:to="loc_srt_ConsolidationItemsDomain_EB9EF1D8F85E9CB5164F634593D944CB_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_BCB7B3EB3EB69D22D591634593D991B3" xlink:to="loc_srt_ConsolidationItemsDomain_EB9EF1D8F85E9CB5164F634593D944CB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_CB2B2CBA50E20792EE7D634593DABEBD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_EB9EF1D8F85E9CB5164F634593D944CB" xlink:to="loc_us-gaap_OperatingSegmentsMember_CB2B2CBA50E20792EE7D634593DABEBD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2451322157BE0682CBEB634593DA5E08" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_796AB62D5CD6043380F7634593D93EF5" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2451322157BE0682CBEB634593DA5E08" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2451322157BE0682CBEB634593DA5E08" xlink:to="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2451322157BE0682CBEB634593DA5E08" xlink:to="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_BC7A29194087BA2ED202634593DB2E0D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D" xlink:to="loc_viac_TVEntertainmentSegmentMember_BC7A29194087BA2ED202634593DB2E0D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_EBC1E6FE55DE28FDA54A634593DBFE52" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D" xlink:to="loc_viac_CableNetworksSegmentMember_EBC1E6FE55DE28FDA54A634593DBFE52" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_42469F614591284BB04B634593DB21F8" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_42469F614591284BB04B634593DB21F8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_7F0CFC7E0B04BB5141D2634593DBB74E" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_DD73F5323D857FA697DD634593DA436D" xlink:to="loc_viac_PublishingSegmentMember_7F0CFC7E0B04BB5141D2634593DBB74E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_D34EFE0D78A7662167E0634593DC4077" xlink:to="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillGross" xlink:label="loc_us-gaap_GoodwillGross_05D7E35B9696205C48B1634593DCF31D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_us-gaap_GoodwillGross_05D7E35B9696205C48B1634593DCF31D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_95BB4CD12F4895A33409634593DD0A78" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_95BB4CD12F4895A33409634593DD0A78" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_7B7EF75257A38D471B4B634593DDD8D5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_us-gaap_Goodwill_7B7EF75257A38D471B4B634593DDD8D5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillAcquiredDisposedDuringPeriod" xlink:label="loc_viac_GoodwillAcquiredDisposedDuringPeriod_EB3D7FA775DED4991D07634593DD24AA" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_viac_GoodwillAcquiredDisposedDuringPeriod_EB3D7FA775DED4991D07634593DD24AA" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillAccumulatedImpairmentAcquiredDisposedDuringPeriod" xlink:label="loc_viac_GoodwillAccumulatedImpairmentAcquiredDisposedDuringPeriod_5024777EBFC4E0E89764634593DD7BB1" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_viac_GoodwillAccumulatedImpairmentAcquiredDisposedDuringPeriod_5024777EBFC4E0E89764634593DD7BB1" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillAcquiredDisposedDuringPeriodNet" xlink:label="loc_viac_GoodwillAcquiredDisposedDuringPeriodNet_4D62EEA4D8E7DCAC156D634593DD7F11" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_viac_GoodwillAcquiredDisposedDuringPeriodNet_4D62EEA4D8E7DCAC156D634593DD7F11" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_88BCA0DCFC0342EC44D9634593DE1BAC" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_88BCA0DCFC0342EC44D9634593DE1BAC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillAccumulatedImpairmentForeignCurrencyTranslationGainLoss" xlink:label="loc_viac_GoodwillAccumulatedImpairmentForeignCurrencyTranslationGainLoss_F0B59FCBD1D637346CDE634593DE7B17" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_viac_GoodwillAccumulatedImpairmentForeignCurrencyTranslationGainLoss_F0B59FCBD1D637346CDE634593DE7B17" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillForeignCurrencyTranslationGainLossNet" xlink:label="loc_viac_GoodwillForeignCurrencyTranslationGainLossNet_4D33AF6E72D9C89B9C05634593DEB3DE" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_44E9430446AE9E807CDE634593DC7E8B" xlink:to="loc_viac_GoodwillForeignCurrencyTranslationGainLossNet_4D33AF6E72D9C89B9C05634593DEB3DE" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsIntangibleAssetsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E92DF8256213310017CC634593C7E971" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E92DF8256213310017CC634593C7E971" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_BB5653A59ED39BAF955E634593C80CD5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E92DF8256213310017CC634593C7E971" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_BB5653A59ED39BAF955E634593C80CD5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_BB5653A59ED39BAF955E634593C80CD5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_BB5653A59ED39BAF955E634593C80CD5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_6EFC2454B857963B2152634593C88D48" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:to="loc_us-gaap_TradeNamesMember_6EFC2454B857963B2152634593C88D48" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LicensingAgreementsMember" xlink:label="loc_us-gaap_LicensingAgreementsMember_729EFDD9D063E554CE18634593C8DB34" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:to="loc_us-gaap_LicensingAgreementsMember_729EFDD9D063E554CE18634593C8DB34" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CustomerAgreementsMember" xlink:label="loc_viac_CustomerAgreementsMember_EF975DE15C235C66DA5F634593C90341" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:to="loc_viac_CustomerAgreementsMember_EF975DE15C235C66DA5F634593C90341" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_8FF4BFFDECFA74F8E87E634593C9BEDF" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_03F2B78EC884C1BCB0AF634593C8C150" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_8FF4BFFDECFA74F8E87E634593C9BEDF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_B26BBE933777A1C1AE8D634593C9C9F0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E92DF8256213310017CC634593C7E971" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_B26BBE933777A1C1AE8D634593C9C9F0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_B26BBE933777A1C1AE8D634593C9C9F0" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_B26BBE933777A1C1AE8D634593C9C9F0" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingAndBroadcastRightsMember" xlink:label="loc_us-gaap_OperatingAndBroadcastRightsMember_00B6A3A678EA1C717076634593CA07C4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5" xlink:to="loc_us-gaap_OperatingAndBroadcastRightsMember_00B6A3A678EA1C717076634593CA07C4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OperatingandBroadcastRightsInternationalMember" xlink:label="loc_viac_OperatingandBroadcastRightsInternationalMember_8D2C18C96A7A8CD5D6BE634593CAEA1B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5" xlink:to="loc_viac_OperatingandBroadcastRightsInternationalMember_8D2C18C96A7A8CD5D6BE634593CAEA1B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_81F22C6E9BFDB57E6191634593CAB484" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5E7D6323914DF601BC5E634593C987D5" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_81F22C6E9BFDB57E6191634593CAB484" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_F755F97D22D5DA44F1C7634593CBE61B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_F755F97D22D5DA44F1C7634593CBE61B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1CCE4F48F1221381048E634593CBD062" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1CCE4F48F1221381048E634593CBD062" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_E571C8C37DAB100C3C59634593CB8AE9" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_E571C8C37DAB100C3C59634593CB8AE9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_5D642127A89695A3CFCE634593CCC2B7" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_5D642127A89695A3CFCE634593CCC2B7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_6412742D0AB88E159247634593CC7983" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_6412742D0AB88E159247634593CC7983" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_8BFA54DE5C63EF888D14634593CC651F" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_8BD501E9F5C181322C8E634593CA9B41" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_8BFA54DE5C63EF888D14634593CC651F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="viac-20191231.xsd#viac_ImpairmentTestingAssumptionsLineItems" xlink:label="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:type="locator"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ImpairmentTestingAssumptionsTable" xlink:label="loc_viac_ImpairmentTestingAssumptionsTable_8F284B15BC9D4772E293634593E964CB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_viac_ImpairmentTestingAssumptionsTable_8F284B15BC9D4772E293634593E964CB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_FD1998DA140A68B1CB5C634593E9752F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_viac_ImpairmentTestingAssumptionsTable_8F284B15BC9D4772E293634593E964CB" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_FD1998DA140A68B1CB5C634593E9752F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C46C63CB9F03A4862D43634593EA9C6C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FD1998DA140A68B1CB5C634593E9752F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C46C63CB9F03A4862D43634593EA9C6C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C46C63CB9F03A4862D43634593EA9C6C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FD1998DA140A68B1CB5C634593E9752F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C46C63CB9F03A4862D43634593EA9C6C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_1926D3387D6E67D09BCD634593EAA8E7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C46C63CB9F03A4862D43634593EA9C6C" xlink:to="loc_viac_ViacomIncMember_1926D3387D6E67D09BCD634593EAA8E7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ImpairmentTestAxis" xlink:label="loc_viac_ImpairmentTestAxis_3EFA818F298EE8709EEF634593EAD000" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_viac_ImpairmentTestingAssumptionsTable_8F284B15BC9D4772E293634593E964CB" xlink:to="loc_viac_ImpairmentTestAxis_3EFA818F298EE8709EEF634593EAD000" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ImpairmentTestDomain" xlink:label="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_viac_ImpairmentTestAxis_3EFA818F298EE8709EEF634593EAD000" xlink:to="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17_default" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ImpairmentTestDomain" xlink:label="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_viac_ImpairmentTestAxis_3EFA818F298EE8709EEF634593EAD000" xlink:to="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FCCLicensesImpairmentTestTelevisionStationsMember" xlink:label="loc_viac_FCCLicensesImpairmentTestTelevisionStationsMember_CE65953919CBE6EAD743634593EB1DE2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17" xlink:to="loc_viac_FCCLicensesImpairmentTestTelevisionStationsMember_CE65953919CBE6EAD743634593EB1DE2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_InternationalBroadcastLicenseMember" xlink:label="loc_viac_InternationalBroadcastLicenseMember_90FF8CE62962A1731D7B634593EB0351" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestDomain_9A76BC7520F307C40FE0634593EACB17" xlink:to="loc_viac_InternationalBroadcastLicenseMember_90FF8CE62962A1731D7B634593EB0351" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_0CBE021C46EBB61177D6634593EB9603" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_viac_ImpairmentTestingAssumptionsTable_8F284B15BC9D4772E293634593E964CB" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_0CBE021C46EBB61177D6634593EB9603" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_D6874E553EBF52EE7C1D634593EC473A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_0CBE021C46EBB61177D6634593EB9603" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_D6874E553EBF52EE7C1D634593EC473A_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_0CBE021C46EBB61177D6634593EB9603" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_D6874E553EBF52EE7C1D634593EC473A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_E6C5F9ABBEDB1DCE75BC634593ECC449" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_D6874E553EBF52EE7C1D634593EC473A" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_E6C5F9ABBEDB1DCE75BC634593ECC449" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_NumberOfMarketsWithBookValueOfFCCLicenses" xlink:label="loc_viac_NumberOfMarketsWithBookValueOfFCCLicenses_DB9D620BAFEBC93E9ED0634593EC8B3A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_viac_NumberOfMarketsWithBookValueOfFCCLicenses_DB9D620BAFEBC93E9ED0634593EC8B3A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NumberOfReportingUnits" xlink:label="loc_us-gaap_NumberOfReportingUnits_1F8A39FC724EE74F5F75634593ED4D8C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_us-gaap_NumberOfReportingUnits_1F8A39FC724EE74F5F75634593ED4D8C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PreMergerNumberofReportingUnits" xlink:label="loc_viac_PreMergerNumberofReportingUnits_60837EFEA9658ECBFA2C634593EDCEE0" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_viac_PreMergerNumberofReportingUnits_60837EFEA9658ECBFA2C634593EDCEE0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GoodwillandIntangibleAssetsMeasurementInput" xlink:label="loc_viac_GoodwillandIntangibleAssetsMeasurementInput_2417811EBF63AC0D33D1634593ED9584" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_viac_GoodwillandIntangibleAssetsMeasurementInput_2417811EBF63AC0D33D1634593ED9584" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PerpetualNominalGrowthRate" xlink:label="loc_viac_PerpetualNominalGrowthRate_6EC05BBF44C6B8B56C68634593EE37B1" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_viac_PerpetualNominalGrowthRate_6EC05BBF44C6B8B56C68634593EE37B1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_F51A4628644FB856D0D7634593EE0D5F" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_F51A4628644FB856D0D7634593EE0D5F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_186CB973520D2E77233B634593EECC0D" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_ImpairmentTestingAssumptionsLineItems_280F4914119790C8DA2D634593ECF8E2" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_186CB973520D2E77233B634593EECC0D" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxes" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesDeferredIncomeTaxAssetsAndLiabilitiesDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesEffectiveIncomeTaxRateReconciliationDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_24FE1F3BAB6B6A6A2A7363459157CCD2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_24FE1F3BAB6B6A6A2A7363459157CCD2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_ACE813CFC017B047A43F634591571948" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_24FE1F3BAB6B6A6A2A7363459157CCD2" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_ACE813CFC017B047A43F634591571948" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_6B5433EA7071404D398863459157C426_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_ACE813CFC017B047A43F634591571948" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_6B5433EA7071404D398863459157C426_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_6B5433EA7071404D398863459157C426" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_ACE813CFC017B047A43F634591571948" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_6B5433EA7071404D398863459157C426" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSTelevisionCityMember" xlink:label="loc_viac_CBSTelevisionCityMember_B6E920CF6DF37F7F50A763459158C34E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_6B5433EA7071404D398863459157C426" xlink:to="loc_viac_CBSTelevisionCityMember_B6E920CF6DF37F7F50A763459158C34E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_7FF3D388B82D9372AFFF634591586924" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_7FF3D388B82D9372AFFF634591586924" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_A3BA45A330619810B00263459159488E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_A3BA45A330619810B00263459159488E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:label="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_8DB27E3352C42EA66CBD63459159EDFF" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_8DB27E3352C42EA66CBD63459159EDFF" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_IncomeTaxReconciliationReorganizationOfForeignOperations" xlink:label="loc_viac_IncomeTaxReconciliationReorganizationOfForeignOperations_7652F98CD91E44730302634591592E44" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_IncomeTaxReconciliationReorganizationOfForeignOperations_7652F98CD91E44730302634591592E44" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_IncomeTaxReconciliationBankruptcyOfInvestee" xlink:label="loc_viac_IncomeTaxReconciliationBankruptcyOfInvestee_D16D34E2CC52B7968F2F63459159D824" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_IncomeTaxReconciliationBankruptcyOfInvestee_D16D34E2CC52B7968F2F63459159D824" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsForeign" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_A860216B17D7FFBEF07A6345915ACD2A" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_A860216B17D7FFBEF07A6345915ACD2A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_IncomeTaxReconciliationTaxCutsAndJobsActOf2017ProvisionalIncomeTaxExpenseBenefit" xlink:label="loc_viac_IncomeTaxReconciliationTaxCutsAndJobsActOf2017ProvisionalIncomeTaxExpenseBenefit_1D053C79B2B0E4E8625C6345915AFDCE" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_IncomeTaxReconciliationTaxCutsAndJobsActOf2017ProvisionalIncomeTaxExpenseBenefit_1D053C79B2B0E4E8625C6345915AFDCE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationPriorYearIncomeTaxes" xlink:label="loc_us-gaap_IncomeTaxReconciliationPriorYearIncomeTaxes_1A67506B264504AB01C16386EF1BE0C6" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationPriorYearIncomeTaxes_1A67506B264504AB01C16386EF1BE0C6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_IncomeTaxReconciliationBusinessCombination" xlink:label="loc_viac_IncomeTaxReconciliationBusinessCombination_54518D6244A33E475EF56345915A2F89" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_IncomeTaxReconciliationBusinessCombination_54518D6244A33E475EF56345915A2F89" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_2E59E79FAE65654106236345915B0A23" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_2E59E79FAE65654106236345915B0A23" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TaxBenefitRealizedFromEmployeeStockOptionExercisesAndRestrictedShareVests" xlink:label="loc_viac_TaxBenefitRealizedFromEmployeeStockOptionExercisesAndRestrictedShareVests_40995BD002E1FBA33D176345915B26C7" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_TaxBenefitRealizedFromEmployeeStockOptionExercisesAndRestrictedShareVests_40995BD002E1FBA33D176345915B26C7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities" xlink:label="loc_us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities_85A7BE1A72A2C5AA62476345915B9C33" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities_85A7BE1A72A2C5AA62476345915B9C33" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_IncomeTaxReconciliationNewAccountingPronouncements" xlink:label="loc_viac_IncomeTaxReconciliationNewAccountingPronouncements_96BECE4BF0C2D30079236345915B057A" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_viac_IncomeTaxReconciliationNewAccountingPronouncements_96BECE4BF0C2D30079236345915B057A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_9F13BAE7C76EDAEE7DE66345915B583E" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_9F13BAE7C76EDAEE7DE66345915B583E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_CB606A86A18930A1C9126345915C6FF9" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_C11D689C864BFB18D01663459158B631" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_CB606A86A18930A1C9126345915C6FF9" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesIncomeLossFromContinuingOperationsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_BBA8B9095259F7C48FF363B27576B11E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_BBA8B9095259F7C48FF363B27576B11E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_2F1C59872D6AE1FE702F63B2757655C4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_BBA8B9095259F7C48FF363B27576B11E" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_2F1C59872D6AE1FE702F63B2757655C4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_75DB5B152AE6F58EAE7563B27577D444_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_2F1C59872D6AE1FE702F63B2757655C4" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_75DB5B152AE6F58EAE7563B27577D444_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_2F1C59872D6AE1FE702F63B2757655C4" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_75DB5B152AE6F58EAE7563B27577D444" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="loc_us-gaap_ForeignCountryMember_42461BC268AD938F0B7663B275779AED" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_75DB5B152AE6F58EAE7563B27577D444" xlink:to="loc_us-gaap_ForeignCountryMember_42461BC268AD938F0B7663B275779AED" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_F386CE61275F997EFE7963B275770E26" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_BBA8B9095259F7C48FF363B27576B11E" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_F386CE61275F997EFE7963B275770E26" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_E952C271700D1037A04463B275783663_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_F386CE61275F997EFE7963B275770E26" xlink:to="loc_us-gaap_RelatedPartyDomain_E952C271700D1037A04463B275783663_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_E952C271700D1037A04463B275783663" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_F386CE61275F997EFE7963B275770E26" xlink:to="loc_us-gaap_RelatedPartyDomain_E952C271700D1037A04463B275783663" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvesteeMember" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_A61E55267FA49146625263B275786B73" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_E952C271700D1037A04463B275783663" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_A61E55267FA49146625263B275786B73" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:label="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_40D057308A321BF883D263B27578BF47" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_40D057308A321BF883D263B27578BF47" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_0515192A533B3DA0975263B2757976D2" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_0515192A533B3DA0975263B2757976D2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3433E48CE7236F26107363B27579D321" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3433E48CE7236F26107363B27579D321" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets_DF53267B3A6E223E730963B27579EB68" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets_DF53267B3A6E223E730963B27579EB68" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaap_OperatingLossCarryforwards_637887B6058E16FAF3EE63B27579A433" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_OperatingLossCarryforwards_637887B6058E16FAF3EE63B27579A433" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_0E0B976E9D50687AB29963B2757982E2" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_0E0B976E9D50687AB29963B2757982E2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit_698725A639CBC25B0F3863B27579825F" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit_698725A639CBC25B0F3863B27579825F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense_CFD9B4DE3393F6E9BFC963B2757A6899" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense_CFD9B4DE3393F6E9BFC963B2757A6899" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense_D76A129FC91C96CE35C063B2757A6BCF" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense_D76A129FC91C96CE35C063B2757A6BCF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit_BEC8E7ED95C1DD1A9D3A63B2757A6DF4" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit_BEC8E7ED95C1DD1A9D3A63B2757A6DF4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_BE80563C92C7B776258663B2757A17F5" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_BE80563C92C7B776258663B2757A17F5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_209F488BD44147DB726563B2757A5BCF" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_209F488BD44147DB726563B2757A5BCF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_52C9E1DB9860D764FA2E63B2757A764C" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_52C9E1DB9860D764FA2E63B2757A764C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_21F8065EF748C10DBA4B63B2757B7D0B" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_21F8065EF748C10DBA4B63B2757B7D0B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_505D8C88AFEB1DF455AE63B2757BA2D5" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_505D8C88AFEB1DF455AE63B2757BA2D5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_UnrecognizedTaxBenefitsDecreaseResultingfromPriorPeriodTaxPositionsTransitionTax" xlink:label="loc_viac_UnrecognizedTaxBenefitsDecreaseResultingfromPriorPeriodTaxPositionsTransitionTax_2BE243A5161A1DE8403263B2757B36CB" xlink:type="locator"/>

<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1A4F0300713D0EBC155E63B27578F6F3" xlink:to="loc_viac_UnrecognizedTaxBenefitsDecreaseResultingfromPriorPeriodTaxPositionsTransitionTax_2BE243A5161A1DE8403263B2757B36CB" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesProvisionForIncomeTaxesDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/Leases" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesBalanceSheetAmountsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesFutureLeaseIncomeAsLessorDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesFutureMinimumPaymentsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesFutureMinimumPaymentsPriorToAdoptionDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesLeaseCostDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_D7FF7767A53A2F6EC6DE6345925DCCE3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_D7FF7767A53A2F6EC6DE6345925DCCE3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4B4AD8F3FECDD91E61E66345925D8443" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_D7FF7767A53A2F6EC6DE6345925DCCE3" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4B4AD8F3FECDD91E61E66345925D8443" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_19C30B720D30A6F30D4A6345925D2145_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4B4AD8F3FECDD91E61E66345925D8443" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_19C30B720D30A6F30D4A6345925D2145_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4B4AD8F3FECDD91E61E66345925D8443" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_19C30B720D30A6F30D4A6345925D2145" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentContinuingOperationsMember" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_8765669C2022CA5C75416345925E5274" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_19C30B720D30A6F30D4A6345925D2145" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_8765669C2022CA5C75416345925E5274" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_1EBB7028C3D3973CB8976345925E7A50" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_19C30B720D30A6F30D4A6345925D2145" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_1EBB7028C3D3973CB8976345925E7A50" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_A7E411ADF7BA672E5AEF6345925E8DC0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_D7FF7767A53A2F6EC6DE6345925DCCE3" xlink:to="loc_srt_RangeAxis_A7E411ADF7BA672E5AEF6345925E8DC0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_A7E411ADF7BA672E5AEF6345925E8DC0" xlink:to="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_A7E411ADF7BA672E5AEF6345925E8DC0" xlink:to="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_1EBCD5384E667F6E6EE36345925F702E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50" xlink:to="loc_srt_MinimumMember_1EBCD5384E667F6E6EE36345925F702E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_B269A95B120C1890E9EA6345925F01A2" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_C27D21921F4CFBBA30ED6345925FCB50" xlink:to="loc_srt_MaximumMember_B269A95B120C1890E9EA6345925F01A2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals_0E2B1DF7DE6A4C02678E6345926004C5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals_0E2B1DF7DE6A4C02678E6345926004C5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeaseAndRentalExpense" xlink:label="loc_us-gaap_LeaseAndRentalExpense_DF5805371BABC5C0BFCB634592600EE0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_us-gaap_LeaseAndRentalExpense_DF5805371BABC5C0BFCB634592600EE0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:label="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_FD1A3F158A314397BCA86345926003DF" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_FD1A3F158A314397BCA86345926003DF" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_LesseeOperatingLeaseLeaseNotYetCommencedFutureUndiscountedLeasePayments" xlink:label="loc_viac_LesseeOperatingLeaseLeaseNotYetCommencedFutureUndiscountedLeasePayments_1F5D9A7F6A99AEAB2DC063459260E4A7" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_viac_LesseeOperatingLeaseLeaseNotYetCommencedFutureUndiscountedLeasePayments_1F5D9A7F6A99AEAB2DC063459260E4A7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLeaseIncome" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_1AF28F396D192607AD5E634592618D61" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_DBBAA007340018122F4B634592606437" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncome_1AF28F396D192607AD5E634592618D61" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesOperatingAndFinancingCashFlowsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/LeasesWeightedAverageDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefits" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsAccumulatedBenefitObligationInExcessOfPlanAssetsDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsAssumptionsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_B69053851057DC908A04634590C75B28" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D2D21630C6216178C62E634590C4788C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_B69053851057DC908A04634590C75B28" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D2D21630C6216178C62E634590C4788C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2FB17BF3E5444A39FB0B634590C4AB3A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D2D21630C6216178C62E634590C4788C" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2FB17BF3E5444A39FB0B634590C4AB3A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_879AE0F02D64E0BB7354634590C4D3C8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2FB17BF3E5444A39FB0B634590C4AB3A" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_879AE0F02D64E0BB7354634590C4D3C8_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2FB17BF3E5444A39FB0B634590C4AB3A" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_879AE0F02D64E0BB7354634590C4D3C8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_C3CB05E10B5BAD4562CD634590C56CBC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_879AE0F02D64E0BB7354634590C4D3C8" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_C3CB05E10B5BAD4562CD634590C56CBC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_6B5E5072B3E2ED4B0640634590C542EE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_879AE0F02D64E0BB7354634590C4D3C8" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_6B5E5072B3E2ED4B0640634590C542EE" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_573B90AE4B22C34556B5634590C5BE79" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D2D21630C6216178C62E634590C4788C" xlink:to="loc_dei_LegalEntityAxis_573B90AE4B22C34556B5634590C5BE79" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_B1AE3747BBB7B89B36FE634590C5214D_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_573B90AE4B22C34556B5634590C5BE79" xlink:to="loc_dei_EntityDomain_B1AE3747BBB7B89B36FE634590C5214D_default" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_B1AE3747BBB7B89B36FE634590C5214D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_573B90AE4B22C34556B5634590C5BE79" xlink:to="loc_dei_EntityDomain_B1AE3747BBB7B89B36FE634590C5214D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_BF7581FC4751F0468DC9634590C633FD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_B1AE3747BBB7B89B36FE634590C5214D" xlink:to="loc_viac_ViacomIncMember_BF7581FC4751F0468DC9634590C633FD" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_HealthCareTrendRateAxis" xlink:label="loc_viac_HealthCareTrendRateAxis_2D9BF7C22004E35D1FB4634590C6D857" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D2D21630C6216178C62E634590C4788C" xlink:to="loc_viac_HealthCareTrendRateAxis_2D9BF7C22004E35D1FB4634590C6D857" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_HealthCareTrendRateDomain" xlink:label="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_viac_HealthCareTrendRateAxis_2D9BF7C22004E35D1FB4634590C6D857" xlink:to="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9_default" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_HealthCareTrendRateDomain" xlink:label="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_viac_HealthCareTrendRateAxis_2D9BF7C22004E35D1FB4634590C6D857" xlink:to="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_Pre65Member" xlink:label="loc_viac_Pre65Member_FB257E770FDAF136C969634590C79E99" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9" xlink:to="loc_viac_Pre65Member_FB257E770FDAF136C969634590C79E99" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_Post65Member" xlink:label="loc_viac_Post65Member_6358F34FCD01CFCFCA96634590C7E025" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_HealthCareTrendRateDomain_BF73DD2DF16B54E3F7C4634590C667D9" xlink:to="loc_viac_Post65Member_6358F34FCD01CFCFCA96634590C7E025" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_DD23348A977E72AE563C634590C7A84E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_B69053851057DC908A04634590C75B28" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_DD23348A977E72AE563C634590C7A84E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_3D7CFB05EF22E75504F7634590C8CC65" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_DD23348A977E72AE563C634590C7A84E" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_3D7CFB05EF22E75504F7634590C8CC65" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_AFFA26DE69315B7E59B0634590C80E94" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_DD23348A977E72AE563C634590C7A84E" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_AFFA26DE69315B7E59B0634590C80E94" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_6FE6ACFC9222E47A5B25634590C941BD" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_B69053851057DC908A04634590C75B28" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_6FE6ACFC9222E47A5B25634590C941BD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_097A8FB65194691BE6A8634590C90844" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_6FE6ACFC9222E47A5B25634590C941BD" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_097A8FB65194691BE6A8634590C90844" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_FD003E5FEAD4EE327C64634590C94C7E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_6FE6ACFC9222E47A5B25634590C941BD" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_FD003E5FEAD4EE327C64634590C94C7E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_4C66DD10A39EA35665B2634590C9BDCF" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_6FE6ACFC9222E47A5B25634590C941BD" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_4C66DD10A39EA35665B2634590C9BDCF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_AEAF6D4F0B525D08AD8F634590C98C12" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_B69053851057DC908A04634590C75B28" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_AEAF6D4F0B525D08AD8F634590C98C12" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_93DFB96924FB2D2156D8634590CAE100" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_AEAF6D4F0B525D08AD8F634590C98C12" xlink:to="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_93DFB96924FB2D2156D8634590CAE100" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1" xlink:label="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_7A73D888C538808D4830634590CA2590" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_AEAF6D4F0B525D08AD8F634590C98C12" xlink:to="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_7A73D888C538808D4830634590CA2590" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsChangeInBenefitObligationDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_16170FE87243AABF96A5634591181060" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_16170FE87243AABF96A5634591181060" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusAxis" xlink:label="loc_us-gaap_RetirementPlanTaxStatusAxis_226250E5724FE675BD8063459118DEF6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_16170FE87243AABF96A5634591181060" xlink:to="loc_us-gaap_RetirementPlanTaxStatusAxis_226250E5724FE675BD8063459118DEF6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusDomain" xlink:label="loc_us-gaap_RetirementPlanTaxStatusDomain_C5BF6649F854BD449D59634591181670_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_226250E5724FE675BD8063459118DEF6" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_C5BF6649F854BD449D59634591181670_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_226250E5724FE675BD8063459118DEF6" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_C5BF6649F854BD449D59634591181670" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_QualifiedPlanMember" xlink:label="loc_us-gaap_QualifiedPlanMember_2EC46A7875828F89172D634591189C4C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTaxStatusDomain_C5BF6649F854BD449D59634591181670" xlink:to="loc_us-gaap_QualifiedPlanMember_2EC46A7875828F89172D634591189C4C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_E7AA18DEDED62DDA321B634591191F6F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_16170FE87243AABF96A5634591181060" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_E7AA18DEDED62DDA321B634591191F6F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E7AA18DEDED62DDA321B634591191F6F" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E7AA18DEDED62DDA321B634591191F6F" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_1C2BF71157C036CFE4C66345911A847C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_1C2BF71157C036CFE4C66345911A847C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_6E30187C021B35B8145E6345911A5E7D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_DB1A2BBD2AD96283893663459119249E" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_6E30187C021B35B8145E6345911A5E7D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_22B69C948A77E0902E136345911AF283" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_16170FE87243AABF96A5634591181060" xlink:to="loc_us-gaap_RetirementPlanNameAxis_22B69C948A77E0902E136345911AF283" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_2046661ABEA2D45CEAC76345911AB924_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_22B69C948A77E0902E136345911AF283" xlink:to="loc_us-gaap_RetirementPlanNameDomain_2046661ABEA2D45CEAC76345911AB924_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_22B69C948A77E0902E136345911AF283" xlink:to="loc_us-gaap_RetirementPlanNameDomain_2046661ABEA2D45CEAC76345911AB924" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GroupAnnuityPurchaseMember" xlink:label="loc_viac_GroupAnnuityPurchaseMember_434C24500A2034D357946345911B3BDE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_2046661ABEA2D45CEAC76345911AB924" xlink:to="loc_viac_GroupAnnuityPurchaseMember_434C24500A2034D357946345911B3BDE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BenefitPlanServicePeriod" xlink:label="loc_viac_BenefitPlanServicePeriod_533EFC164277852A5D1E6345911BCBC3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_viac_BenefitPlanServicePeriod_533EFC164277852A5D1E6345911BCBC3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PercentOfPlanAssetsFairValueInvestedInCompanyCommonStock" xlink:label="loc_viac_PercentOfPlanAssetsFairValueInvestedInCompanyCommonStock_09A62CEECDD7135F57926345911C6736" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_viac_PercentOfPlanAssetsFairValueInvestedInCompanyCommonStock_09A62CEECDD7135F57926345911C6736" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanSettlementsBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanSettlementsBenefitObligation_B0808FB3BB60A86EEA836345911C5373" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_us-gaap_DefinedBenefitPlanSettlementsBenefitObligation_B0808FB3BB60A86EEA836345911C5373" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_EE8ABB913050C3EE853A6345911C2BDC" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_EE8ABB913050C3EE853A6345911C2BDC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DefinedBenefitPlanEmployerDiscretionaryContributionAmount" xlink:label="loc_viac_DefinedBenefitPlanEmployerDiscretionaryContributionAmount_9969B601C369E144455B6345911CEA7E" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_viac_DefinedBenefitPlanEmployerDiscretionaryContributionAmount_9969B601C369E144455B6345911CEA7E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DB858148A54211E6F41D6345911BE687" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_6E978F68D2643FD13BD46345911DC880" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_6E978F68D2643FD13BD46345911DC880" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_ECE79D2217F87C93F8536345911D4A8D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_ECE79D2217F87C93F8536345911D4A8D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_72A467F8DC55512AD4426345911D1DC0" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_72A467F8DC55512AD4426345911D1DC0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_E1456A95D07B5550E2676345911E5DAE" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_E1456A95D07B5550E2676345911E5DAE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_DDD8275150DF6DE253FE6345911E9D8B" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_DDD8275150DF6DE253FE6345911E9D8B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_9D24F250091975CDEE296345911E2234" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_9D24F250091975CDEE296345911E2234" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationPrescriptionDrugSubsidyReceipt" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationPrescriptionDrugSubsidyReceipt_C77ABC123510C74AF8DB6345911EE1CF" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_FCC855A942870AECFB736345911CB104" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationPrescriptionDrugSubsidyReceipt_C77ABC123510C74AF8DB6345911EE1CF" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsChangeInPlanAssetsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_BE5F0068A3BD3CBA15F36345910BE349" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_EFD5D39EC6C425A507926345910932FE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_BE5F0068A3BD3CBA15F36345910BE349" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_EFD5D39EC6C425A507926345910932FE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_4DF0B389ACF4F2C81ADE6345910AE5E8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_EFD5D39EC6C425A507926345910932FE" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_4DF0B389ACF4F2C81ADE6345910AE5E8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4DF0B389ACF4F2C81ADE6345910AE5E8" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4DF0B389ACF4F2C81ADE6345910AE5E8" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_798B8D8A3CCBD0B7BACA6345910B0D8B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_798B8D8A3CCBD0B7BACA6345910B0D8B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_8D70E2BE7D455F7506E46345910B7A33" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_9B3889FC84891B0618DF6345910A9B52" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_8D70E2BE7D455F7506E46345910B7A33" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_BE5F0068A3BD3CBA15F36345910BE349" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_B251FCF2BEA292D0EED96345910C6349" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_B251FCF2BEA292D0EED96345910C6349" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_1F68418809F8211C55AF6345910CB3A9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_1F68418809F8211C55AF6345910CB3A9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_62E8BD0AD99D49964E3C6345910C9B96" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_62E8BD0AD99D49964E3C6345910C9B96" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_3934F1E2E8B01D6C17036345910D03F1" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_3934F1E2E8B01D6C17036345910D03F1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_A99606B4247C688A9CD56345910DF987" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_A99606B4247C688A9CD56345910DF987" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsPrescriptionDrugSubsidyReceipt" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsPrescriptionDrugSubsidyReceipt_EB2F6B62C2B627332B796345910DCBC1" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_CD119DE10C6235C1DC436345910B3879" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsPrescriptionDrugSubsidyReceipt_EB2F6B62C2B627332B796345910DCBC1" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsComponentsOfNetPeriodicBenefitCostAndAmountsRecognizedInOtherComprehensiveIncomeLossDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_9025F94C9BC2C44A0C3C634590DCC190" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_B44E62DBB9880F0E35C6634590DA5B4A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_9025F94C9BC2C44A0C3C634590DCC190" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_B44E62DBB9880F0E35C6634590DA5B4A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_BC9354C444D2AA56C0BE634590DA2194" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_B44E62DBB9880F0E35C6634590DA5B4A" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_BC9354C444D2AA56C0BE634590DA2194" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_BC9354C444D2AA56C0BE634590DA2194" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_BC9354C444D2AA56C0BE634590DA2194" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_03348F068FF5F2C8B904634590DB8FC8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_03348F068FF5F2C8B904634590DB8FC8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_FCCAB043D40A1FF04CE6634590DBD559" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_18F36F1AA0751D314D74634590DB6CED" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_FCCAB043D40A1FF04CE6634590DBD559" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_BCD6DE7ED7ABFC728545634590DB4AFE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_B44E62DBB9880F0E35C6634590DA5B4A" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_BCD6DE7ED7ABFC728545634590DB4AFE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_9156BACCBD2F98C55E1A634590DC833E_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_BCD6DE7ED7ABFC728545634590DB4AFE" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_9156BACCBD2F98C55E1A634590DC833E_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_9156BACCBD2F98C55E1A634590DC833E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_BCD6DE7ED7ABFC728545634590DB4AFE" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_9156BACCBD2F98C55E1A634590DC833E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_D9F9F630972D6C22A027634590DCC36C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_9156BACCBD2F98C55E1A634590DC833E" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_D9F9F630972D6C22A027634590DCC36C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_9025F94C9BC2C44A0C3C634590DCC190" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_1352B8786E8CBF2A7AFA634590DDE084" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_1352B8786E8CBF2A7AFA634590DDE084" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_EE6EA940AB8A38B31192634590DED9C6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_EE6EA940AB8A38B31192634590DED9C6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_0C9FB1DB302DCA065F95634590DE8CD2" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_0C9FB1DB302DCA065F95634590DE8CD2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_739D18077792D97A8413634590DEB423" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_739D18077792D97A8413634590DEB423" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_B864DB9E94CC1503A6EA634590DEF9A3" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_B864DB9E94CC1503A6EA634590DEF9A3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_6DED2935311407E1359D634590DFB9C9" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_6DED2935311407E1359D634590DFB9C9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_B6633D7E838FF57CD592634590DF293C" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_7D890BC139FDD4C39B1F634590DD7471" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_B6633D7E838FF57CD592634590DF293C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_9025F94C9BC2C44A0C3C634590DCC190" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_0DB1AAAD6A16F0BF1A5D634590DF1360" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_0DB1AAAD6A16F0BF1A5D634590DF1360" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_485A81599EADF4173ECE634590DFFE78" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_485A81599EADF4173ECE634590DFFE78" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_F9569001D4AA45C95763634590E000B7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_F9569001D4AA45C95763634590E000B7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax_048E2CB32C7E02AE6E2D634590E07AE2" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax_048E2CB32C7E02AE6E2D634590E07AE2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_3CF05F3D87347F7D7B5F634590E0C8A3" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_3CF05F3D87347F7D7B5F634590E0C8A3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_FEE1CCB3BB8193A3E9C1634590E136C1" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_FEE1CCB3BB8193A3E9C1634590E136C1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_0D8E458EC7AC8633D88F634590E1448A" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTaxAbstract_E51837C7A491291626E1634590DF0D5D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_0D8E458EC7AC8633D88F634590E1448A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_DB66734EF11968CC721A634590E1A09C" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_9025F94C9BC2C44A0C3C634590DCC190" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_DB66734EF11968CC721A634590E1A09C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_26A31A2060B89079F543634590E1893C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_DB66734EF11968CC721A634590E1A09C" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_26A31A2060B89079F543634590E1893C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_841A0F402AFD56EE15A6634590E171E0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_DB66734EF11968CC721A634590E1A09C" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_841A0F402AFD56EE15A6634590E171E0" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsDefinedContributionPlansDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFairValueMeasurementsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7141E027789129996B35634590A02602" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7141E027789129996B35634590A02602" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_26AB4870F457456ACF33634590998A61" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_26AB4870F457456ACF33634590998A61" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_B0A6B3862134D029CA3A63459099F036_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_26AB4870F457456ACF33634590998A61" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B0A6B3862134D029CA3A63459099F036_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_26AB4870F457456ACF33634590998A61" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B0A6B3862134D029CA3A63459099F036" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_4DE30A9245E8CA51C9746345909AC892" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_B0A6B3862134D029CA3A63459099F036" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_4DE30A9245E8CA51C9746345909AC892" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B85136F10A8B6B685FB16345909A6908" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B85136F10A8B6B685FB16345909A6908" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B85136F10A8B6B685FB16345909A6908" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B85136F10A8B6B685FB16345909A6908" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_FBC15F360981D5372D106345909B90C7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_FBC15F360981D5372D106345909B90C7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_FE455FED8AD60DED35806345909B899C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_FE455FED8AD60DED35806345909B899C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_F139CB45EBF254B6EDB46345909B1048" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_F139CB45EBF254B6EDB46345909B1048" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_B4AC966C598DF9A9A3BF6345909C15FD" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4EFA9A35CC4C2C24CA196345909B726B" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_B4AC966C598DF9A9A3BF6345909C15FD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_9BFD6F2ED3D3135576CD6345909C1D71" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_9BFD6F2ED3D3135576CD6345909C1D71" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_9BFD6F2ED3D3135576CD6345909C1D71" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_9BFD6F2ED3D3135576CD6345909C1D71" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_5C6A429958F4E6519AEF6345909D3591" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_5C6A429958F4E6519AEF6345909D3591" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_5029D82C4B491399B76A6345909D3FB9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_5029D82C4B491399B76A6345909D3FB9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_USGovernmentDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_739360CB1DFBC8CE5E546345909DA71E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_739360CB1DFBC8CE5E546345909DA71E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_87CECC8D292A659FF8CA6345909DEC1E" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_87CECC8D292A659FF8CA6345909DEC1E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="loc_us-gaap_AssetBackedSecuritiesMember_BD4B0922C229B565C5736345909DE38A" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_AssetBackedSecuritiesMember_BD4B0922C229B565C5736345909DE38A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesUsLargeCapMember" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsLargeCapMember_9A5EAD56D90B18E2031C6345909EA363" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsLargeCapMember_9A5EAD56D90B18E2031C6345909EA363" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesUsSmallCapMember" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsSmallCapMember_47CDF519D21F4FB62EBA6345909E585E" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsSmallCapMember_47CDF519D21F4FB62EBA6345909E585E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherInvestmentsMember" xlink:label="loc_us-gaap_OtherInvestmentsMember_1E808859130597FF36846345909E0BB1" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_OtherInvestmentsMember_1E808859130597FF36846345909E0BB1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_DDFE1A0A7619A3C8979E6345909EC6B4" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_DDFE1A0A7619A3C8979E6345909EC6B4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_LimitedPartnershipsMember" xlink:label="loc_viac_LimitedPartnershipsMember_63F66C1A92035199D81F6345909F9316" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_viac_LimitedPartnershipsMember_63F66C1A92035199D81F6345909F9316" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MutualFundMember" xlink:label="loc_us-gaap_MutualFundMember_FA26397AF6813A6E34E26345909FE659" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_91953708AFF9114AAA1D6345909C5C4D" xlink:to="loc_us-gaap_MutualFundMember_FA26397AF6813A6E34E26345909FE659" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_96B7F2D1B9D91E1AA7CA6345909FDB51" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2E4688178F0830C1F289634590990A1A" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_96B7F2D1B9D91E1AA7CA6345909FDB51" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_6B7FDB4A1583A3025B1B6345909FDB84_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_96B7F2D1B9D91E1AA7CA6345909FDB51" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_6B7FDB4A1583A3025B1B6345909FDB84_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_6B7FDB4A1583A3025B1B6345909FDB84" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_96B7F2D1B9D91E1AA7CA6345909FDB51" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_6B7FDB4A1583A3025B1B6345909FDB84" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_6E500E1DFF9CEC42FB63634590A0222D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_6B7FDB4A1583A3025B1B6345909FDB84" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_6E500E1DFF9CEC42FB63634590A0222D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_7DDFC4B09F9EE559CA36634590A08341" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7141E027789129996B35634590A02602" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_7DDFC4B09F9EE559CA36634590A08341" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFundedStatusAndAmountsRecognizedInAccumulatedOtherComprehensiveIncomeLossOnConsolidatedBalanceSheetsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_52DAFDB4B8233AB599C6634590F11F8E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_52DAFDB4B8233AB599C6634590F11F8E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_4D54B5AFDED6F6E62DCB634590F1A1AA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_52DAFDB4B8233AB599C6634590F11F8E" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_4D54B5AFDED6F6E62DCB634590F1A1AA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4D54B5AFDED6F6E62DCB634590F1A1AA" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4D54B5AFDED6F6E62DCB634590F1A1AA" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_8BD1BE7A884B60EC832F634590F2D80D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_8BD1BE7A884B60EC832F634590F2D80D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_52001A079F7BFD3FD216634590F241C7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_83D358DAAD0D08005C08634590F2BCC6" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_52001A079F7BFD3FD216634590F241C7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_7F307B8D12A5D832B719634590F30730" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_7F307B8D12A5D832B719634590F30730" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_31F9984574CCACFC3447634590F31E23" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_31F9984574CCACFC3447634590F31E23" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeShareOfEquityInvesteeBeforeTax" xlink:label="loc_viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeShareOfEquityInvesteeBeforeTax_F6EF27682E66E9AED7FE634590F4ABEA" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeShareOfEquityInvesteeBeforeTax_F6EF27682E66E9AED7FE634590F4ABEA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_E59D8BD1F737ADDC22C8634590F40885" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_E59D8BD1F737ADDC22C8634590F40885" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeDeferredTax" xlink:label="loc_viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeDeferredTax_687F6A2B1B6C195CA483634590F47E80" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_viac_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeDeferredTax_687F6A2B1B6C195CA483634590F47E80" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_0B4E227845DD2790B9FF634590F45666" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_0B4E227845DD2790B9FF634590F45666" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_4590FF82DFB42CBA5705634590F46B72" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0F5E506CC3E1C2ED88E8634590F31A37" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_4590FF82DFB42CBA5705634590F46B72" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFundedStatusOfPensionAndPostretirementBenefitObligationsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_AF6951089D85563EC150634590FD6C3E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_AF6951089D85563EC150634590FD6C3E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_F4A4D727A1BAF96D05B1634590FE85E4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_AF6951089D85563EC150634590FD6C3E" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_F4A4D727A1BAF96D05B1634590FE85E4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_F4A4D727A1BAF96D05B1634590FE85E4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_F4A4D727A1BAF96D05B1634590FE85E4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_64D5FF3C325EDEFFBB32634590FE2DF7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_64D5FF3C325EDEFFBB32634590FE2DF7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_A8AD06CF5C02D22042BD634590FFA4C3" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_7419BCB0D0D49BEF50AE634590FE91E2" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_A8AD06CF5C02D22042BD634590FFA4C3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_DFA2685D4F3444D25231634590FF8885" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_AF6951089D85563EC150634590FD6C3E" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_DFA2685D4F3444D25231634590FF8885" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_B82377415564AA02F764634590FF0FEB_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_DFA2685D4F3444D25231634590FF8885" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_B82377415564AA02F764634590FF0FEB_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_DFA2685D4F3444D25231634590FF8885" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_B82377415564AA02F764634590FF0FEB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_16BECDEBCDA4EA092F386345910009DC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_B82377415564AA02F764634590FF0FEB" xlink:to="loc_us-gaap_ForeignPlanMember_16BECDEBCDA4EA092F386345910009DC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusAxis" xlink:label="loc_us-gaap_RetirementPlanTaxStatusAxis_04C4B141168AB99545C2634591007243" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_AF6951089D85563EC150634590FD6C3E" xlink:to="loc_us-gaap_RetirementPlanTaxStatusAxis_04C4B141168AB99545C2634591007243" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusDomain" xlink:label="loc_us-gaap_RetirementPlanTaxStatusDomain_FD815D0B56FD8FE9EB2863459100ED61_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_04C4B141168AB99545C2634591007243" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_FD815D0B56FD8FE9EB2863459100ED61_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusDomain" xlink:label="loc_us-gaap_RetirementPlanTaxStatusDomain_FD815D0B56FD8FE9EB2863459100ED61" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_04C4B141168AB99545C2634591007243" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_FD815D0B56FD8FE9EB2863459100ED61" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_QualifiedPlanMember" xlink:label="loc_us-gaap_QualifiedPlanMember_9473BD4F0E299E863A8663459101AE3E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTaxStatusDomain_FD815D0B56FD8FE9EB2863459100ED61" xlink:to="loc_us-gaap_QualifiedPlanMember_9473BD4F0E299E863A8663459101AE3E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_81D20664B99AC9F035C563459101B100" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_81D20664B99AC9F035C563459101B100" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_98320298496EB6F3EEE563459102BB7A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_98320298496EB6F3EEE563459102BB7A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_831B4F7327D8960E470663459102D5F5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_831B4F7327D8960E470663459102D5F5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_63B626EB9AFE3A2C35526345910294E0" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_63B626EB9AFE3A2C35526345910294E0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_B482DEEEBC43AB2801946345910264C9" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_5324EB805F006014868863459101466B" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_B482DEEEBC43AB2801946345910264C9" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsFutureBenefitPaymentsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_E0C3E6191E40F1EA97886345907DB895" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_E0C3E6191E40F1EA97886345907DB895" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_6A073558F40F873E7A486345907D7AC3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_E0C3E6191E40F1EA97886345907DB895" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_6A073558F40F873E7A486345907D7AC3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_6A073558F40F873E7A486345907D7AC3" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_6A073558F40F873E7A486345907D7AC3" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_0A83EE6A48507AFA64876345907E54EE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_0A83EE6A48507AFA64876345907E54EE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2D7B3680364AD2D355A36345907F6DE3" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_F4D0C07DF39DF3816C076345907E52BF" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2D7B3680364AD2D355A36345907F6DE3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusAxis" xlink:label="loc_us-gaap_RetirementPlanTaxStatusAxis_34650BA0E53481A4017B6345907F2E86" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_E0C3E6191E40F1EA97886345907DB895" xlink:to="loc_us-gaap_RetirementPlanTaxStatusAxis_34650BA0E53481A4017B6345907F2E86" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusDomain" xlink:label="loc_us-gaap_RetirementPlanTaxStatusDomain_7AF2E38E1C24E913346C6345907F6F21_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_34650BA0E53481A4017B6345907F2E86" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_7AF2E38E1C24E913346C6345907F6F21_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTaxStatusDomain" xlink:label="loc_us-gaap_RetirementPlanTaxStatusDomain_7AF2E38E1C24E913346C6345907F6F21" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTaxStatusAxis_34650BA0E53481A4017B6345907F2E86" xlink:to="loc_us-gaap_RetirementPlanTaxStatusDomain_7AF2E38E1C24E913346C6345907F6F21" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonqualifiedPlanMember" xlink:label="loc_us-gaap_NonqualifiedPlanMember_0D6D2CB333691F6E5E726345907FC28E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTaxStatusDomain_7AF2E38E1C24E913346C6345907F6F21" xlink:to="loc_us-gaap_NonqualifiedPlanMember_0D6D2CB333691F6E5E726345907FC28E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_26A60D267764404DC6E6634590805E6A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_26A60D267764404DC6E6634590805E6A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_F0C4E91106C8C251E744634590802333" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_F0C4E91106C8C251E744634590802333" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_6ACEC56ED3B079D72BB563459080E6B6" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_6ACEC56ED3B079D72BB563459080E6B6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_192FDE6BE1CF0C9DDCDA63459081B005" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_192FDE6BE1CF0C9DDCDA63459081B005" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_7ECC57F7F4CFF363AB33634590816B61" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_7ECC57F7F4CFF363AB33634590816B61" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_9936FCD032C0AA2020136345908133A8" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_9936FCD032C0AA2020136345908133A8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_2573D987BD813B01E170634590818F44" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_2573D987BD813B01E170634590818F44" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract" xlink:label="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C923EF440223AF81E84F634590808355" xlink:to="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsNextTwelveMonths" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsNextTwelveMonths_C49BFB22BAABF6E1E6D863459082BCC2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsNextTwelveMonths_C49BFB22BAABF6E1E6D863459082BCC2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsYearTwo1" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearTwo1_6956939B1504F61AAB7563459082D762" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearTwo1_6956939B1504F61AAB7563459082D762" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsYearThree1" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearThree1_9AD71B1C2906CF64374B634590820C54" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearThree1_9AD71B1C2906CF64374B634590820C54" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsYearFour1" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearFour1_63E85F54727CBBFA34FA634590837702" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearFour1_63E85F54727CBBFA34FA634590837702" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsYearFive1" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearFive1_941D567F89234924F5AE63459083485A" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsYearFive1_941D567F89234924F5AE63459083485A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrescriptionDrugSubsidyReceiptsAfterYearFive" xlink:label="loc_us-gaap_PrescriptionDrugSubsidyReceiptsAfterYearFive_9C6D3D3F8BA5F346A3C1634590830ED9" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract_C622A46C930DC6B9F36E634590819952" xlink:to="loc_us-gaap_PrescriptionDrugSubsidyReceiptsAfterYearFive_9C6D3D3F8BA5F346A3C1634590830ED9" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsMultiemployerPensionAndPostretirementBenefitPlansDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansLineItems" xlink:label="loc_us-gaap_MultiemployerPlansLineItems_B9DCB8BE2302ABF2D1A2638D760CBEBB" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfMultiemployerPlansTable" xlink:label="loc_us-gaap_ScheduleOfMultiemployerPlansTable_2CE1102380F699C77192638D76078488" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MultiemployerPlansLineItems_B9DCB8BE2302ABF2D1A2638D760CBEBB" xlink:to="loc_us-gaap_ScheduleOfMultiemployerPlansTable_2CE1102380F699C77192638D76078488" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlanTypeAxis" xlink:label="loc_us-gaap_MultiemployerPlanTypeAxis_9E1110B54268D7D0C4C0638D76072D9A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfMultiemployerPlansTable_2CE1102380F699C77192638D76078488" xlink:to="loc_us-gaap_MultiemployerPlanTypeAxis_9E1110B54268D7D0C4C0638D76072D9A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansTypeDomain" xlink:label="loc_us-gaap_MultiemployerPlansTypeDomain_AC18648F72AA5D0BB763638D76084C14_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MultiemployerPlanTypeAxis_9E1110B54268D7D0C4C0638D76072D9A" xlink:to="loc_us-gaap_MultiemployerPlansTypeDomain_AC18648F72AA5D0BB763638D76084C14_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MultiemployerPlanTypeAxis_9E1110B54268D7D0C4C0638D76072D9A" xlink:to="loc_us-gaap_MultiemployerPlansTypeDomain_AC18648F72AA5D0BB763638D76084C14" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansPensionMember" xlink:label="loc_us-gaap_MultiemployerPlansPensionMember_0980F669542E297E4E2D638D76082C7D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlansTypeDomain_AC18648F72AA5D0BB763638D76084C14" xlink:to="loc_us-gaap_MultiemployerPlansPensionMember_0980F669542E297E4E2D638D76082C7D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansPostretirementBenefitMember" xlink:label="loc_us-gaap_MultiemployerPlansPostretirementBenefitMember_A37D6211542B6423444D638D76089D83" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlansTypeDomain_AC18648F72AA5D0BB763638D76084C14" xlink:to="loc_us-gaap_MultiemployerPlansPostretirementBenefitMember_A37D6211542B6423444D638D76089D83" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlanNameAxis" xlink:label="loc_us-gaap_MultiemployerPlanNameAxis_E8B0D3BC81496537700A638D760902AC" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfMultiemployerPlansTable_2CE1102380F699C77192638D76078488" xlink:to="loc_us-gaap_MultiemployerPlanNameAxis_E8B0D3BC81496537700A638D760902AC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlanNameDomain" xlink:label="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MultiemployerPlanNameAxis_E8B0D3BC81496537700A638D760902AC" xlink:to="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MultiemployerPlanNameAxis_E8B0D3BC81496537700A638D760902AC" xlink:to="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AftraRetirementPlanMember" xlink:label="loc_viac_AftraRetirementPlanMember_D1828279410CA9A773F8638D7609A000" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_AftraRetirementPlanMember_D1828279410CA9A773F8638D7609A000" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_DirectorsGuildOfAmericaProducerMember" xlink:label="loc_viac_DirectorsGuildOfAmericaProducerMember_EEDB020007F783F76E90638D760AB33C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_DirectorsGuildOfAmericaProducerMember_EEDB020007F783F76E90638D760AB33C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProducerWritersGuildOfAmericaMember" xlink:label="loc_viac_ProducerWritersGuildOfAmericaMember_ADCEB960EEE6126A1001638D760A3D13" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_ProducerWritersGuildOfAmericaMember_ADCEB960EEE6126A1001638D760A3D13" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ScreenActorsGuildProducersMember" xlink:label="loc_viac_ScreenActorsGuildProducersMember_0975E359D83CD1C72941638D760A7EE6" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_ScreenActorsGuildProducersMember_0975E359D83CD1C72941638D760A7EE6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_MotionPictureIndustryMember" xlink:label="loc_viac_MotionPictureIndustryMember_A696F5C26222201D441E638D760A8C4E" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_MotionPictureIndustryMember_A696F5C26222201D441E638D760A8C4E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_I.A.T.S.E.LocalNo.33PensionTrustFundMember" xlink:label="loc_viac_I.A.T.S.E.LocalNo.33PensionTrustFundMember_BD2432E603E5929F27D8638D760BAD88" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_viac_I.A.T.S.E.LocalNo.33PensionTrustFundMember_BD2432E603E5929F27D8638D760BAD88" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlanIndividuallyInsignificantMultiemployerPlansMember" xlink:label="loc_us-gaap_MultiemployerPlanIndividuallyInsignificantMultiemployerPlansMember_347B548DA4BD9D50CBBE638D760BED7B" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlanNameDomain_BD4EDC562691FD6B3F81638D7609DBE8" xlink:to="loc_us-gaap_MultiemployerPlanIndividuallyInsignificantMultiemployerPlansMember_347B548DA4BD9D50CBBE638D760BED7B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_E654891BC5D89123AA93638D760BA22D" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfMultiemployerPlansTable_2CE1102380F699C77192638D76078488" xlink:to="loc_srt_RangeAxis_E654891BC5D89123AA93638D760BA22D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_E654891BC5D89123AA93638D760BA22D" xlink:to="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_E654891BC5D89123AA93638D760BA22D" xlink:to="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_1D6EB31B7DF0EDCDA3D4638D760CAC1B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC" xlink:to="loc_srt_MinimumMember_1D6EB31B7DF0EDCDA3D4638D760CAC1B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_3C784397194A861191B1638D760C2BD9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_F475448E6D5558AA974A638D760B23EC" xlink:to="loc_srt_MaximumMember_3C784397194A861191B1638D760C2BD9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansCertifiedZoneStatus" xlink:label="loc_us-gaap_MultiemployerPlansCertifiedZoneStatus_485341B1541AAAACC774638D760D8304" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlansLineItems_B9DCB8BE2302ABF2D1A2638D760CBEBB" xlink:to="loc_us-gaap_MultiemployerPlansCertifiedZoneStatus_485341B1541AAAACC774638D760D8304" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlanContributionsByEmployer" xlink:label="loc_us-gaap_MultiemployerPlanContributionsByEmployer_AC105888CF6C66C1EC51638D760D4211" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlansLineItems_B9DCB8BE2302ABF2D1A2638D760CBEBB" xlink:to="loc_us-gaap_MultiemployerPlanContributionsByEmployer_AC105888CF6C66C1EC51638D760D4211" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDate" xlink:label="loc_us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDate_B847F9E73E5E8A06E793638D760EA3D5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MultiemployerPlansLineItems_B9DCB8BE2302ABF2D1A2638D760CBEBB" xlink:to="loc_us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDate_B847F9E73E5E8A06E793638D760EA3D5" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsPlanAssetAllocationsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DA2CD4C6EC7D8FD70DE3634590B042C2" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DA2CD4C6EC7D8FD70DE3634590B042C2" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_6CD5312EE05968614A22634590AB0F0F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_6CD5312EE05968614A22634590AB0F0F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_843C5593FD615793C05E634590ABE59C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_6CD5312EE05968614A22634590AB0F0F" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_843C5593FD615793C05E634590ABE59C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_843C5593FD615793C05E634590ABE59C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_6CD5312EE05968614A22634590AB0F0F" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_843C5593FD615793C05E634590ABE59C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DomesticPlanMember" xlink:label="loc_us-gaap_DomesticPlanMember_94E0E0A3C825FE6FB893634590ACB754" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_843C5593FD615793C05E634590ABE59C" xlink:to="loc_us-gaap_DomesticPlanMember_94E0E0A3C825FE6FB893634590ACB754" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_11471F97DA0A172329BC634590AC10F9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_94E0E0A3C825FE6FB893634590ACB754" xlink:to="loc_country_US_11471F97DA0A172329BC634590AC10F9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_BF4E6CB62E1845E0DD50634590AD7B8B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:to="loc_srt_RangeAxis_BF4E6CB62E1845E0DD50634590AD7B8B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_BF4E6CB62E1845E0DD50634590AD7B8B" xlink:to="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_BF4E6CB62E1845E0DD50634590AD7B8B" xlink:to="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_7296E426D04768FF9994634590AD1141" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31" xlink:to="loc_srt_MinimumMember_7296E426D04768FF9994634590AD1141" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_21D39F25C79CEC38A4D4634590ADE0CE" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_36DF0704D23225DE0872634590ADBD31" xlink:to="loc_srt_MaximumMember_21D39F25C79CEC38A4D4634590ADE0CE" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_F1F29E3346E10C7107BA634590ADDC08" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:to="loc_dei_LegalEntityAxis_F1F29E3346E10C7107BA634590ADDC08" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_10F76B5C540E8B276F31634590AE73B7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_F1F29E3346E10C7107BA634590ADDC08" xlink:to="loc_dei_EntityDomain_10F76B5C540E8B276F31634590AE73B7_default" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_10F76B5C540E8B276F31634590AE73B7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_F1F29E3346E10C7107BA634590ADDC08" xlink:to="loc_dei_EntityDomain_10F76B5C540E8B276F31634590AE73B7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_C403ABD075ED98159240634590AEA4AE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_10F76B5C540E8B276F31634590AE73B7" xlink:to="loc_viac_ViacomIncMember_C403ABD075ED98159240634590AEA4AE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2DE9AF176A4B70E79434634590AE59FC" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_39F1E91DE42F73B0586D634590AB7A99" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2DE9AF176A4B70E79434634590AE59FC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2DE9AF176A4B70E79434634590AE59FC" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2DE9AF176A4B70E79434634590AE59FC" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FixedIncomeSecuritiesMember" xlink:label="loc_us-gaap_FixedIncomeSecuritiesMember_138EBF43894BBA8DC785634590AF28DE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:to="loc_us-gaap_FixedIncomeSecuritiesMember_138EBF43894BBA8DC785634590AF28DE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_3C2AB8459E2B3106834A634590AFAB95" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_3C2AB8459E2B3106834A634590AFAB95" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_80546B1C52645DC718C7634590B0B9F7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_80546B1C52645DC718C7634590B0B9F7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_2C233C20194255DA598D634590B0F6CB" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_F818EC282B46EBBDE378634590AFDBB7" xlink:to="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_2C233C20194255DA598D634590B0F6CB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_D9ADBDF99BF02F8F279C634590B0ECD9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DA2CD4C6EC7D8FD70DE3634590B042C2" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_D9ADBDF99BF02F8F279C634590B0ECD9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_FC88804B2F9DE71C5074634590B184FD" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_DA2CD4C6EC7D8FD70DE3634590B042C2" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_FC88804B2F9DE71C5074634590B184FD" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsSensitivityDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_246D623FCBF9F05D5630634590B9AC4F" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CFFE37C553CADB4E938634590B7DC99" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_246D623FCBF9F05D5630634590B9AC4F" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CFFE37C553CADB4E938634590B7DC99" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_4DBD2E9098344B1C522E634590B8AFBE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CFFE37C553CADB4E938634590B7DC99" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_4DBD2E9098344B1C522E634590B8AFBE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B870289E695CF80A9990634590B83A52_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4DBD2E9098344B1C522E634590B8AFBE" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B870289E695CF80A9990634590B83A52_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B870289E695CF80A9990634590B83A52" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4DBD2E9098344B1C522E634590B8AFBE" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B870289E695CF80A9990634590B83A52" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_5552ADD27E186267D042634590B94EE1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_B870289E695CF80A9990634590B83A52" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_5552ADD27E186267D042634590B94EE1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_246D623FCBF9F05D5630634590B9AC4F" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_66059DB11D68348689B5634590B976CB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_66059DB11D68348689B5634590B976CB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_FCF15D42965707928BB3634590BA7C34" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_FCF15D42965707928BB3634590BA7C34" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_6D4413AB8280C4AF2B1D634590BA9317" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_6D4413AB8280C4AF2B1D634590BA9317" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_D278F688B3BAA5CB4421634590BA06BF" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_F3DC5D9AF93D23DED03B634590B98C49" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_D278F688B3BAA5CB4421634590BA06BF" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PensionAndOtherPostretirementBenefitsTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ProgrammingAndOtherInventory" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ProgrammingAndOtherInventoryDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InventoryLineItems" xlink:label="loc_us-gaap_InventoryLineItems_8F692A81AC26F392876E634594096553" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InventoryCurrentTable" xlink:label="loc_us-gaap_InventoryCurrentTable_DEF87D21FF8749A4228C634594088F89" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_8F692A81AC26F392876E634594096553" xlink:to="loc_us-gaap_InventoryCurrentTable_DEF87D21FF8749A4228C634594088F89" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PublicUtilitiesInventoryAxis" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_B2F0AB6220A9A44F6E2C63459408B076" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_DEF87D21FF8749A4228C634594088F89" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_B2F0AB6220A9A44F6E2C63459408B076" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_6069B6831955A5CA5F4763459408C131_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_B2F0AB6220A9A44F6E2C63459408B076" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_6069B6831955A5CA5F4763459408C131_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_B2F0AB6220A9A44F6E2C63459408B076" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_6069B6831955A5CA5F4763459408C131" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmInventoryMember" xlink:label="loc_viac_FilmInventoryMember_0440CD5D0254FE75B9B9634594093B01" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_6069B6831955A5CA5F4763459408C131" xlink:to="loc_viac_FilmInventoryMember_0440CD5D0254FE75B9B9634594093B01" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PercentageOfUnamortizedFilmCosts" xlink:label="loc_us-gaap_PercentageOfUnamortizedFilmCosts_93958A7826C9E140399F63459409B6B2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_8F692A81AC26F392876E634594096553" xlink:to="loc_us-gaap_PercentageOfUnamortizedFilmCosts_93958A7826C9E140399F63459409B6B2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProgrammingCharges" xlink:label="loc_viac_ProgrammingCharges_8BA9C3B112EEC628607D6345940A457F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_8F692A81AC26F392876E634594096553" xlink:to="loc_viac_ProgrammingCharges_8BA9C3B112EEC628607D6345940A457F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ProgrammingAndOtherInventoryTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PropertyAndEquipment" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PropertyAndEquipmentDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9473AE9235D8D1945B2D6345941EA1AC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9473AE9235D8D1945B2D6345941EA1AC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_9C6593CFEF48F645794C6345941E14D8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9473AE9235D8D1945B2D6345941EA1AC" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_9C6593CFEF48F645794C6345941E14D8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_9C6593CFEF48F645794C6345941E14D8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_9C6593CFEF48F645794C6345941E14D8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_ECFC861E49EA2568FA9F6345941F5110" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A" xlink:to="loc_us-gaap_LandMember_ECFC861E49EA2568FA9F6345941F5110" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_179C3C55EF158625E7B06345941FA934" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A" xlink:to="loc_us-gaap_BuildingMember_179C3C55EF158625E7B06345941FA934" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquipmentMember" xlink:label="loc_us-gaap_EquipmentMember_81115AC436082BE63CE86345941FFCF1" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_DC81242F6C8DAA4967CA6345941F686A" xlink:to="loc_us-gaap_EquipmentMember_81115AC436082BE63CE86345941FFCF1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_304E88FDD7C7CBC6648F634594201729" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9473AE9235D8D1945B2D6345941EA1AC" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_304E88FDD7C7CBC6648F634594201729" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_4B7DA32F1DA00FF5080E63459420BCDE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_304E88FDD7C7CBC6648F634594201729" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_4B7DA32F1DA00FF5080E63459420BCDE_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_4B7DA32F1DA00FF5080E63459420BCDE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_304E88FDD7C7CBC6648F634594201729" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_4B7DA32F1DA00FF5080E63459420BCDE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSTelevisionCityMember" xlink:label="loc_viac_CBSTelevisionCityMember_3931BBB33933FEB8350163459420A89E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_4B7DA32F1DA00FF5080E63459420BCDE" xlink:to="loc_viac_CBSTelevisionCityMember_3931BBB33933FEB8350163459420A89E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_4320437B522FE54FEE41634594215F45" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9473AE9235D8D1945B2D6345941EA1AC" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_4320437B522FE54FEE41634594215F45" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_0CBB6EB367846B5855356345942171B7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_4320437B522FE54FEE41634594215F45" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_0CBB6EB367846B5855356345942171B7_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_0CBB6EB367846B5855356345942171B7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_4320437B522FE54FEE41634594215F45" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_0CBB6EB367846B5855356345942171B7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GainOnSaleOfAssetsMember" xlink:label="loc_viac_GainOnSaleOfAssetsMember_4E4FDF2C7C4C83BB0D27634594213CD1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_0CBB6EB367846B5855356345942171B7" xlink:to="loc_viac_GainOnSaleOfAssetsMember_4E4FDF2C7C4C83BB0D27634594213CD1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_8EBAEB4EB9A3D8EE33BF634594221FA8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_8EBAEB4EB9A3D8EE33BF634594221FA8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FinanceLeaseRightofUseAssetBeforeAccumulatedAmortization" xlink:label="loc_viac_FinanceLeaseRightofUseAssetBeforeAccumulatedAmortization_A2DFE2EB2AD430DFD9EC634594224307" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_FinanceLeaseRightofUseAssetBeforeAccumulatedAmortization_A2DFE2EB2AD430DFD9EC634594224307" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:label="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetBeforeAccumulatedDepreciationAndAmortization_C6F44BA9A0D7D1EAE346634594236D5D" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetBeforeAccumulatedDepreciationAndAmortization_C6F44BA9A0D7D1EAE346634594236D5D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PropertyPlantandEquipmentandFinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization" xlink:label="loc_viac_PropertyPlantandEquipmentandFinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization_A509192D39977073D751634594238D17" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_PropertyPlantandEquipmentandFinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization_A509192D39977073D751634594238D17" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:label="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization_0B0A46CF9EF21AC975C163459423DA02" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_PropertyPlantAndEquipmentAndFinanceLeaseRightofUseAssetAfterAccumulatedDepreciationAndAmortization_0B0A46CF9EF21AC975C163459423DA02" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization" xlink:label="loc_viac_FinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization_077E3D1A0187DDA48BB8634594231AF1" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_FinanceLeaseRightofUseAssetAccumulatedDepreciationandAmortization_077E3D1A0187DDA48BB8634594231AF1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_97CB6B87BD538E5926816345942344C4" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_Depreciation_97CB6B87BD538E5926816345942344C4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_DE743E4B2DB4C6525330634594237695" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_DE743E4B2DB4C6525330634594237695" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CapitalLeasesIncomeStatementAmortizationExpense" xlink:label="loc_us-gaap_CapitalLeasesIncomeStatementAmortizationExpense_E83C12D32498F28ED95863459424E177" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_CapitalLeasesIncomeStatementAmortizationExpense_E83C12D32498F28ED95863459424E177" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_5F99E709C1CD4E02809663459424695D" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_5F99E709C1CD4E02809663459424695D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GuaranteedCashFlowPeriod" xlink:label="loc_viac_GuaranteedCashFlowPeriod_902EFDB2488EA75AA12F634594242D6F" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_GuaranteedCashFlowPeriod_902EFDB2488EA75AA12F634594242D6F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_486A85D9A3DF5FED0A1E63459425895F" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_486A85D9A3DF5FED0A1E63459425895F" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GainLossOnDispositionOfAssetsNetOfTax" xlink:label="loc_viac_GainLossOnDispositionOfAssetsNetOfTax_A9AE7C707035C85170C6634594258893" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_94FFAFA9F8A097215F8A63459421204C" xlink:to="loc_viac_GainLossOnDispositionOfAssetsNetOfTax_A9AE7C707035C85170C6634594258893" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/PropertyAndEquipmentTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/QuarterlyFinancialDataUnaudited" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/QuarterlyFinancialDataUnauditedDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectOfFourthQuarterEventsLineItems" xlink:label="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEffectOfFourthQuarterEventsTable" xlink:label="loc_us-gaap_ScheduleOfEffectOfFourthQuarterEventsTable_456518026AF4D006918663458DF71202" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_ScheduleOfEffectOfFourthQuarterEventsTable_456518026AF4D006918663458DF71202" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_93E1D8F3C989AFAB1BCE63458DF7DCB9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEffectOfFourthQuarterEventsTable_456518026AF4D006918663458DF71202" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_93E1D8F3C989AFAB1BCE63458DF7DCB9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_553487FA104897A8B1C863458DF7A274_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_93E1D8F3C989AFAB1BCE63458DF7DCB9" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_553487FA104897A8B1C863458DF7A274_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_553487FA104897A8B1C863458DF7A274" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis_93E1D8F3C989AFAB1BCE63458DF7DCB9" xlink:to="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_553487FA104897A8B1C863458DF7A274" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSTelevisionCityMember" xlink:label="loc_viac_CBSTelevisionCityMember_6F259B56E69EC8D88C0263458DFD9E95" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongLivedAssetsHeldForSaleNameDomain_553487FA104897A8B1C863458DF7A274" xlink:to="loc_viac_CBSTelevisionCityMember_6F259B56E69EC8D88C0263458DFD9E95" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_558CA01B190DF9D8F1EC63458DFE19A3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_558CA01B190DF9D8F1EC63458DFE19A3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_F7A27FDD929E961E7D5463458DFEB02F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_OperatingIncomeLoss_F7A27FDD929E961E7D5463458DFEB02F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_990A33AC7007F3892F1263458DFEBAA6" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_990A33AC7007F3892F1263458DFEBAA6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_FBE485DC99D89C63F90863458DFE8256" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_ProfitLoss_FBE485DC99D89C63F90863458DFE8256" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_7153179D370086FDE0CD63458DFF97E4" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_7153179D370086FDE0CD63458DFF97E4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_987D71DB6A00384EAC7163458DFF666E" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_NetIncomeLoss_987D71DB6A00384EAC7163458DFF666E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareBasicAbstract" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_445E125A3106D795996663458DFF1922" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_445E125A3106D795996663458DFF1922" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicShare" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_ADBE3B46FF2C24FA31A063458DFFB349" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_445E125A3106D795996663458DFF1922" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_ADBE3B46FF2C24FA31A063458DFFB349" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_666858F789CE2AAAFAED63458E004BB6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_445E125A3106D795996663458DFF1922" xlink:to="loc_us-gaap_EarningsPerShareBasic_666858F789CE2AAAFAED63458E004BB6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareDilutedAbstract" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_85A2B44004ED533B19AF63458E007758" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_85A2B44004ED533B19AF63458E007758" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_F97679D749645B50D53263458E00BA00" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_85A2B44004ED533B19AF63458E007758" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_F97679D749645B50D53263458E00BA00" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_F5B72F9A5791E02C6E5563458E001DE7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_85A2B44004ED533B19AF63458E007758" xlink:to="loc_us-gaap_EarningsPerShareDiluted_F5B72F9A5791E02C6E5563458E001DE7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_2FEE53D5F99F7CF76EDB63458E01FCB2" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_2FEE53D5F99F7CF76EDB63458E01FCB2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_D4E4D22586D102A5CC9C63458E01066B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_2FEE53D5F99F7CF76EDB63458E01FCB2" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_D4E4D22586D102A5CC9C63458E01066B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_2AB23E3E22AB1CF7C28C63458E01BD62" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_2FEE53D5F99F7CF76EDB63458E01FCB2" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_2AB23E3E22AB1CF7C28C63458E01BD62" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesAndOther" xlink:label="loc_viac_RestructuringChargesAndOther_CA40B46D75E9381C371E63458E0248D0" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_viac_RestructuringChargesAndOther_CA40B46D75E9381C371E63458E0248D0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ImpactOnTaxProvisionBenefitFromDiscreteItems" xlink:label="loc_viac_ImpactOnTaxProvisionBenefitFromDiscreteItems_C2E86651C8CCF942237C63458E02A26F" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_viac_ImpactOnTaxProvisionBenefitFromDiscreteItems_C2E86651C8CCF942237C63458E02A26F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_770B07B93088E720FBB963458E02AE87" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_770B07B93088E720FBB963458E02AE87" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_GainLossOnDispositionOfAssetsNetOfTax" xlink:label="loc_viac_GainLossOnDispositionOfAssetsNetOfTax_01CBCA366E2E0C6FD93E63458E02EF04" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_viac_GainLossOnDispositionOfAssetsNetOfTax_01CBCA366E2E0C6FD93E63458E02EF04" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProgrammingCharges" xlink:label="loc_viac_ProgrammingCharges_D4A9A3C48208FA4C082463458E0274CE" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectOfFourthQuarterEventsLineItems_6B24755E71A4AFB275BB63458DFD5705" xlink:to="loc_viac_ProgrammingCharges_D4A9A3C48208FA4C082463458E0274CE" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/QuarterlyFinancialDataUnauditedTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RedeemableNoncontrollingInterest" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RedeemableNoncontrollingInterestDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RedeemableNoncontrollingInterestTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RelatedParties" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RelatedPartiesNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C5392050CF459F5E25236345937AF709" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C5392050CF459F5E25236345937AF709" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_6D382438EBF966EBC8866345937A5031" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C5392050CF459F5E25236345937AF709" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_6D382438EBF966EBC8866345937A5031" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_611C6CE84097B085BD306345937AE1E3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_6D382438EBF966EBC8866345937A5031" xlink:to="loc_us-gaap_RelatedPartyDomain_611C6CE84097B085BD306345937AE1E3_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_611C6CE84097B085BD306345937AE1E3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_6D382438EBF966EBC8866345937A5031" xlink:to="loc_us-gaap_RelatedPartyDomain_611C6CE84097B085BD306345937AE1E3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MajorityShareholderMember" xlink:label="loc_us-gaap_MajorityShareholderMember_73A9563D08E2917613576345937B6095" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_611C6CE84097B085BD306345937AE1E3" xlink:to="loc_us-gaap_MajorityShareholderMember_73A9563D08E2917613576345937B6095" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_0AEB231D2C819D7A18246345937B2D6A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C5392050CF459F5E25236345937AF709" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_0AEB231D2C819D7A18246345937B2D6A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ED97667F884E50F1585C6345937BC0DE_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_0AEB231D2C819D7A18246345937B2D6A" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ED97667F884E50F1585C6345937BC0DE_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ED97667F884E50F1585C6345937BC0DE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_0AEB231D2C819D7A18246345937B2D6A" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ED97667F884E50F1585C6345937BC0DE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesAndOtherMember" xlink:label="loc_viac_RestructuringChargesAndOtherMember_80479589EFB9A760831E6345937BE5FC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ED97667F884E50F1585C6345937BC0DE" xlink:to="loc_viac_RestructuringChargesAndOtherMember_80479589EFB9A760831E6345937BE5FC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OwnershipPercentOfClassAStockByControllingStockholder" xlink:label="loc_viac_OwnershipPercentOfClassAStockByControllingStockholder_CE5CEA95AFFDBD9734D26345937CABE1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_viac_OwnershipPercentOfClassAStockByControllingStockholder_CE5CEA95AFFDBD9734D26345937CABE1" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OwnershipPercentOfClassAAndClassBStockByControllingStockholder" xlink:label="loc_viac_OwnershipPercentOfClassAAndClassBStockByControllingStockholder_6AB03CCEE060E820ED096345937C84C4" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_viac_OwnershipPercentOfClassAAndClassBStockByControllingStockholder_6AB03CCEE060E820ED096345937C84C4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ChairmanEmeritusTrustOwnershipPercentageInControllingStockholder" xlink:label="loc_viac_ChairmanEmeritusTrustOwnershipPercentageInControllingStockholder_484AEBFC6CE931E0AA6B6345937D18D5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_viac_ChairmanEmeritusTrustOwnershipPercentageInControllingStockholder_484AEBFC6CE931E0AA6B6345937D18D5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_NumberofTrustees" xlink:label="loc_viac_NumberofTrustees_7E5BA6818E0CCB852AAB6345937D3FB4" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_viac_NumberofTrustees_7E5BA6818E0CCB852AAB6345937D3FB4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfessionalFees" xlink:label="loc_us-gaap_ProfessionalFees_22E798753CFDF4CB666F6345937D5090" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_us-gaap_ProfessionalFees_22E798753CFDF4CB666F6345937D5090" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:label="loc_us-gaap_RevenueFromRelatedParties_7D7CAC7D91523EE9F1626345937DF86F" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_FC522DF089403428B8906345937C7735" xlink:to="loc_us-gaap_RevenueFromRelatedParties_7D7CAC7D91523EE9F1626345937DF86F" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RelatedPartiesScheduleOfRelatedPartyTransactionsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_5DB7EF36D814BC6ECC86634593714371" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C00D257B4DEBDFDC095E63459370C849" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5DB7EF36D814BC6ECC86634593714371" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C00D257B4DEBDFDC095E63459370C849" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B34894E96321720CFFB663459370B0A5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_C00D257B4DEBDFDC095E63459370C849" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B34894E96321720CFFB663459370B0A5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_64D5A6A448550A93A557634593706AD5_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B34894E96321720CFFB663459370B0A5" xlink:to="loc_us-gaap_RelatedPartyDomain_64D5A6A448550A93A557634593706AD5_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_64D5A6A448550A93A557634593706AD5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_B34894E96321720CFFB663459370B0A5" xlink:to="loc_us-gaap_RelatedPartyDomain_64D5A6A448550A93A557634593706AD5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherRelatedPartiesMember" xlink:label="loc_viac_OtherRelatedPartiesMember_9EC0935FB9476ABA28C9634593715D4C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_64D5A6A448550A93A557634593706AD5" xlink:to="loc_viac_OtherRelatedPartiesMember_9EC0935FB9476ABA28C9634593715D4C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherRelatedPartiesConsolidatedStatementsOfEarningsTablesAbstract" xlink:label="loc_viac_OtherRelatedPartiesConsolidatedStatementsOfEarningsTablesAbstract_1BDB8A897B0B840D133B63459371D16C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5DB7EF36D814BC6ECC86634593714371" xlink:to="loc_viac_OtherRelatedPartiesConsolidatedStatementsOfEarningsTablesAbstract_1BDB8A897B0B840D133B63459371D16C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:label="loc_us-gaap_RevenueFromRelatedParties_488B7EA8339919742A2F634593722794" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_OtherRelatedPartiesConsolidatedStatementsOfEarningsTablesAbstract_1BDB8A897B0B840D133B63459371D16C" xlink:to="loc_us-gaap_RevenueFromRelatedParties_488B7EA8339919742A2F634593722794" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_37B75F9EBED72A092DBA63459372FCB8" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_OtherRelatedPartiesConsolidatedStatementsOfEarningsTablesAbstract_1BDB8A897B0B840D133B63459371D16C" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_37B75F9EBED72A092DBA63459372FCB8" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherRelatedPartiesConsolidatedBalanceSheetsTablesAbstract" xlink:label="loc_viac_OtherRelatedPartiesConsolidatedBalanceSheetsTablesAbstract_6C976B8E5E82F54DC6AF63459372160F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5DB7EF36D814BC6ECC86634593714371" xlink:to="loc_viac_OtherRelatedPartiesConsolidatedBalanceSheetsTablesAbstract_6C976B8E5E82F54DC6AF63459372160F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DueFromRelatedPartiesCurrent" xlink:label="loc_us-gaap_DueFromRelatedPartiesCurrent_BB7B30214C0F413338B663459372EB67" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_OtherRelatedPartiesConsolidatedBalanceSheetsTablesAbstract_6C976B8E5E82F54DC6AF63459372160F" xlink:to="loc_us-gaap_DueFromRelatedPartiesCurrent_BB7B30214C0F413338B663459372EB67" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DueToRelatedPartiesCurrent" xlink:label="loc_us-gaap_DueToRelatedPartiesCurrent_D2A0729082BA5738E74D63459373AF55" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_viac_OtherRelatedPartiesConsolidatedBalanceSheetsTablesAbstract_6C976B8E5E82F54DC6AF63459372160F" xlink:to="loc_us-gaap_DueToRelatedPartiesCurrent_D2A0729082BA5738E74D63459373AF55" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RelatedPartiesTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMatters" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5C456B718A42D1AEB7016345939CA531" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5C456B718A42D1AEB7016345939CA531" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_4EF214F0D75C17938BFB6345939CD200" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5C456B718A42D1AEB7016345939CA531" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_4EF214F0D75C17938BFB6345939CD200" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_5692B95702E48AE7FBA36345939DB00D_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_4EF214F0D75C17938BFB6345939CD200" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_5692B95702E48AE7FBA36345939DB00D_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_4EF214F0D75C17938BFB6345939CD200" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_5692B95702E48AE7FBA36345939DB00D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_C250509A604D3A2B958B6345939D4DCB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_5692B95702E48AE7FBA36345939DB00D" xlink:to="loc_us-gaap_EmployeeSeveranceMember_C250509A604D3A2B958B6345939D4DCB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractTerminationMember" xlink:label="loc_us-gaap_ContractTerminationMember_7C4E098CD090C7F414B46345939D9262" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_5692B95702E48AE7FBA36345939DB00D" xlink:to="loc_us-gaap_ContractTerminationMember_7C4E098CD090C7F414B46345939D9262" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_3F74CFBA8342CE99232A6345939E87D5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_RestructuringCharges_3F74CFBA8342CE99232A6345939E87D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="loc_us-gaap_PaymentsForRestructuring_DC2DE49C2854670B397D6345939EC285" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_PaymentsForRestructuring_DC2DE49C2854670B397D6345939EC285" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherCorporateMattersCosts" xlink:label="loc_viac_OtherCorporateMattersCosts_13EE921D0A0F3EF36B486345939E63D5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_viac_OtherCorporateMattersCosts_13EE921D0A0F3EF36B486345939E63D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_6303180238CF81D1A3D36345939F1607" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_6303180238CF81D1A3D36345939F1607" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LitigationSettlementExpense" xlink:label="loc_us-gaap_LitigationSettlementExpense_05E0CB675DB98F46A6546345939FEE23" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_LitigationSettlementExpense_05E0CB675DB98F46A6546345939FEE23" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LegalFees" xlink:label="loc_us-gaap_LegalFees_E8FB08BCB997626AFC466345939F0014" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_us-gaap_LegalFees_E8FB08BCB997626AFC466345939F0014" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProgrammingCharges" xlink:label="loc_viac_ProgrammingCharges_3F56D6D22BDE49C946266345939F9F0A" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_viac_ProgrammingCharges_3F56D6D22BDE49C946266345939F9F0A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringRelatedCosts" xlink:label="loc_viac_RestructuringRelatedCosts_914BFF557987C2DFA74F6345939FD9E0" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_E2DF7F15B412E7F527366345939D848D" xlink:to="loc_viac_RestructuringRelatedCosts_914BFF557987C2DFA74F6345939FD9E0" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersRestructuringAndOtherCorporateMattersDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6C59F829477553C190C8634593A8A97E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6C59F829477553C190C8634593A8A97E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_5BFE7DB88876F1184005634593A8551C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6C59F829477553C190C8634593A8A97E" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_5BFE7DB88876F1184005634593A8551C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_5BFE7DB88876F1184005634593A8551C" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_5BFE7DB88876F1184005634593A8551C" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_CCAD39989FE8800CF353634593A93150" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2" xlink:to="loc_us-gaap_EmployeeSeveranceMember_CCAD39989FE8800CF353634593A93150" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractTerminationMember" xlink:label="loc_us-gaap_ContractTerminationMember_883BF96C62D1ACBC0846634593A9E53D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2" xlink:to="loc_us-gaap_ContractTerminationMember_883BF96C62D1ACBC0846634593A9E53D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AssetImpairmentMember" xlink:label="loc_viac_AssetImpairmentMember_6E58404FA86D8941D81C634593AADABE" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_7FDA2B2FC9179C773F10634593A845E2" xlink:to="loc_viac_AssetImpairmentMember_6E58404FA86D8941D81C634593AADABE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_DB6D7922D638E47057F8634593AAB4C4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_us-gaap_RestructuringCharges_DB6D7922D638E47057F8634593AAB4C4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringRelatedCosts" xlink:label="loc_viac_RestructuringRelatedCosts_A192E1627EAB8AD99BB0634593AA16D5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_viac_RestructuringRelatedCosts_A192E1627EAB8AD99BB0634593AA16D5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_47FC65D0CEA4371C3D5D634593AAE2B5" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_47FC65D0CEA4371C3D5D634593AAE2B5" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_OtherCorporateMattersCosts" xlink:label="loc_viac_OtherCorporateMattersCosts_897A4F54BA1C9186025F634593ABAFC6" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_viac_OtherCorporateMattersCosts_897A4F54BA1C9186025F634593ABAFC6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesAndOther" xlink:label="loc_viac_RestructuringChargesAndOther_92714686B504525C67F5634593ABD2E4" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_viac_RestructuringChargesAndOther_92714686B504525C67F5634593ABD2E4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProgrammingCharges" xlink:label="loc_viac_ProgrammingCharges_8D0AEC84B2CFCAEC4EA3634593AB10C9" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_52B713F64D96E84B2D26634593AA82D5" xlink:to="loc_viac_ProgrammingCharges_8D0AEC84B2CFCAEC4EA3634593AB10C9" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersRollforwardDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_DC7092D48DBDBBD909C86345939290CB" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_C4DC3925BD7A4C344FD96345938E1843" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_DC7092D48DBDBBD909C86345939290CB" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_C4DC3925BD7A4C344FD96345938E1843" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_62B69621798D0588E19F6345938EEFE0" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_C4DC3925BD7A4C344FD96345938E1843" xlink:to="loc_srt_ConsolidationItemsAxis_62B69621798D0588E19F6345938EEFE0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_62B69621798D0588E19F6345938EEFE0" xlink:to="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_62B69621798D0588E19F6345938EEFE0" xlink:to="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_4DBB0B2592F0934971C76345938FECFF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3" xlink:to="loc_us-gaap_OperatingSegmentsMember_4DBB0B2592F0934971C76345938FECFF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_336ED457EB62C8E682A26345938F67C2" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_49F0CB83D5EA030C1AFB6345938F0DA3" xlink:to="loc_us-gaap_CorporateNonSegmentMember_336ED457EB62C8E682A26345938F67C2" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_5450D1DE05501EA21EA163459390E1D9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_C4DC3925BD7A4C344FD96345938E1843" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_5450D1DE05501EA21EA163459390E1D9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5450D1DE05501EA21EA163459390E1D9" xlink:to="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5450D1DE05501EA21EA163459390E1D9" xlink:to="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_B47B24D11AA2FC43462B6345939088F7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:to="loc_viac_TVEntertainmentSegmentMember_B47B24D11AA2FC43462B6345939088F7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_EDE0BBC5132CDDD7CFDE634593902538" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:to="loc_viac_CableNetworksSegmentMember_EDE0BBC5132CDDD7CFDE634593902538" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_1C118E1ECEDE4464FEB863459391204B" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_1C118E1ECEDE4464FEB863459391204B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_0430E80F07AB48F4C8CE63459391EE23" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2A64E30F2E6BD62ABC8B6345939034F4" xlink:to="loc_viac_PublishingSegmentMember_0430E80F07AB48F4C8CE63459391EE23" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_57D370EFD203E11D785763459391AD7E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_C4DC3925BD7A4C344FD96345938E1843" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_57D370EFD203E11D785763459391AD7E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_57D370EFD203E11D785763459391AD7E" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_57D370EFD203E11D785763459391AD7E" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesExcludingStockBasedCompensationMember" xlink:label="loc_viac_RestructuringChargesExcludingStockBasedCompensationMember_5FD8937E1D470EC25A1B6345939231FE" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2" xlink:to="loc_viac_RestructuringChargesExcludingStockBasedCompensationMember_5FD8937E1D470EC25A1B6345939231FE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockBasedCompensationExpenseMember" xlink:label="loc_viac_StockBasedCompensationExpenseMember_5015F89B158211B8CF646345939257BD" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_A82FF4277634F9C9A12A6345939145F2" xlink:to="loc_viac_StockBasedCompensationExpenseMember_5015F89B158211B8CF646345939257BD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringReserveRollForward" xlink:label="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_DC7092D48DBDBBD909C86345939290CB" xlink:to="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_813B1E465349AB5A491C634593933403" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:to="loc_us-gaap_RestructuringReserve_813B1E465349AB5A491C634593933403" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_7DC7B294F020E1DF4FE663459393857D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:to="loc_us-gaap_RestructuringCharges_7DC7B294F020E1DF4FE663459393857D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="loc_us-gaap_PaymentsForRestructuring_D4ADF6E0266A31A5E1D16345939484B7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:to="loc_us-gaap_PaymentsForRestructuring_D4ADF6E0266A31A5E1D16345939484B7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringReserveOtherAdjustment" xlink:label="loc_viac_RestructuringReserveOtherAdjustment_DB3A1CF9CAB13A59ED5F634593944184" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_73893FDCF9708A466358634593925865" xlink:to="loc_viac_RestructuringReserveOtherAdjustment_DB3A1CF9CAB13A59ED5F634593944184" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/RestructuringProgrammingChargesAndOtherCorporateMattersTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_7A7872B4D7C3A2B7A08563458D93A800" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_EB80FE59CDC7EEA2903163458D8F73E5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_7A7872B4D7C3A2B7A08563458D93A800" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_EB80FE59CDC7EEA2903163458D8F73E5" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_A559BA30F28082C96D3163458D905D70" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_EB80FE59CDC7EEA2903163458D8F73E5" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_A559BA30F28082C96D3163458D905D70" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_A559BA30F28082C96D3163458D905D70" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_A559BA30F28082C96D3163458D905D70" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllowanceForCreditLossMember" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_E50B96353A8B0C53C99463458D91F417" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_E50B96353A8B0C53C99463458D91F417" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_D8C3C9331652CC3BE74763458D921B4D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_D8C3C9331652CC3BE74763458D921B4D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InventoryValuationReserveMember" xlink:label="loc_us-gaap_InventoryValuationReserveMember_5DE70E80F0F2566DCCAD63458D92E025" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_60F85D568FB500EC2FF263458D91390F" xlink:to="loc_us-gaap_InventoryValuationReserveMember_5DE70E80F0F2566DCCAD63458D92E025" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_7A7872B4D7C3A2B7A08563458D93A800" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_902DA0FF2C9BA45F0B5D63458D93B609" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_902DA0FF2C9BA45F0B5D63458D93B609" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired_48C3A2FE893A7BD47B8163458D9CDF5E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired_48C3A2FE893A7BD47B8163458D9CDF5E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_14985639EA9E5339EB0663458D9C734F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_14985639EA9E5339EB0663458D9C734F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_91BB63C0958ABA6A6BE363458D9C8A45" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_91BB63C0958ABA6A6BE363458D9C8A45" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_B78928901F75CBC9642B63458D9C5C9D" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_7E4E1CF9B560B60EEB0063458D93404C" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_B78928901F75CBC9642B63458D9C5C9D" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformation" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationAssetsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_DACFD59D7CD59E8A172363458FCC7A89" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_109AB3D467485E5104D963458FC9C22D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_DACFD59D7CD59E8A172363458FCC7A89" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_109AB3D467485E5104D963458FC9C22D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_6A3FD447114E6E938A9763458FC96A5A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_109AB3D467485E5104D963458FC9C22D" xlink:to="loc_srt_ConsolidationItemsAxis_6A3FD447114E6E938A9763458FC96A5A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_6A3FD447114E6E938A9763458FC96A5A" xlink:to="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_6A3FD447114E6E938A9763458FC96A5A" xlink:to="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_C3A1DF673C8EB6B8DC6763458FCA720D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8" xlink:to="loc_us-gaap_OperatingSegmentsMember_C3A1DF673C8EB6B8DC6763458FCA720D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CorporateAndEliminationsMember" xlink:label="loc_viac_CorporateAndEliminationsMember_F2129938BDFD0659163C63458FCAF7BC" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_56A1E78AFE2199BD99FA63458FCA69C8" xlink:to="loc_viac_CorporateAndEliminationsMember_F2129938BDFD0659163C63458FCAF7BC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_BF7D7BDBD02A86CC6A2C63458FCA64D0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_109AB3D467485E5104D963458FC9C22D" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_BF7D7BDBD02A86CC6A2C63458FCA64D0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_BF7D7BDBD02A86CC6A2C63458FCA64D0" xlink:to="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_BF7D7BDBD02A86CC6A2C63458FCA64D0" xlink:to="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_69F059D9877D0FFFD86763458FCB9C31" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:to="loc_viac_TVEntertainmentSegmentMember_69F059D9877D0FFFD86763458FCB9C31" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_96A415890ED00947078363458FCC4CF1" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:to="loc_viac_CableNetworksSegmentMember_96A415890ED00947078363458FCC4CF1" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_D37AD951E5AFAC5904DE63458FCCB62E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_D37AD951E5AFAC5904DE63458FCCB62E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_CD37ACF9E8EF24BDAEA063458FCC9D7E" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_296FADC5D019F9E84F9A63458FCB7D4C" xlink:to="loc_viac_PublishingSegmentMember_CD37ACF9E8EF24BDAEA063458FCC9D7E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_F32B72EE81B8952D7F7663458FCCCCE7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_DACFD59D7CD59E8A172363458FCC7A89" xlink:to="loc_us-gaap_Assets_F32B72EE81B8952D7F7663458FCCCCE7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_6A6808907271F24F8CC963458FCD2833" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_DACFD59D7CD59E8A172363458FCC7A89" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_6A6808907271F24F8CC963458FCD2833" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AssetsHeldForSaleNoncurrent" xlink:label="loc_viac_AssetsHeldForSaleNoncurrent_C0853B583A84A282D03163458FCDBD24" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_DACFD59D7CD59E8A172363458FCC7A89" xlink:to="loc_viac_AssetsHeldForSaleNoncurrent_C0853B583A84A282D03163458FCDBD24" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationCapitalExpendituresDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_3A39293E95A2F770511563458FD9C070" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_67B2D8BDD1500EFE0C7463458FD62651" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_3A39293E95A2F770511563458FD9C070" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_67B2D8BDD1500EFE0C7463458FD62651" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_FCA68B2240FD8BB24D6863458FD6D13E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_67B2D8BDD1500EFE0C7463458FD62651" xlink:to="loc_srt_ConsolidationItemsAxis_FCA68B2240FD8BB24D6863458FD6D13E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_FCA68B2240FD8BB24D6863458FD6D13E" xlink:to="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_FCA68B2240FD8BB24D6863458FD6D13E" xlink:to="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_5980BED4F2CE6BAA14CB63458FD7FE96" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71" xlink:to="loc_us-gaap_OperatingSegmentsMember_5980BED4F2CE6BAA14CB63458FD7FE96" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_8D02D5E4347527A4CD1863458FD7FE3D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3EA7C0F460E5E3C2842E63458FD65E71" xlink:to="loc_us-gaap_CorporateNonSegmentMember_8D02D5E4347527A4CD1863458FD7FE3D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_742A764FB381F30C5FF263458FD77DC7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_67B2D8BDD1500EFE0C7463458FD62651" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_742A764FB381F30C5FF263458FD77DC7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_742A764FB381F30C5FF263458FD77DC7" xlink:to="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_742A764FB381F30C5FF263458FD77DC7" xlink:to="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_035F2A182A668D95D5B163458FD833F9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:to="loc_viac_TVEntertainmentSegmentMember_035F2A182A668D95D5B163458FD833F9" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_3AD39675346A7FBE2C9A63458FD8477C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:to="loc_viac_CableNetworksSegmentMember_3AD39675346A7FBE2C9A63458FD8477C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_9216B86E82E3EC27287163458FD8FD89" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_9216B86E82E3EC27287163458FD8FD89" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_158FFA80B92C016485C663458FD9347A" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_11176F4E2FCD82B056DC63458FD7D42C" xlink:to="loc_viac_PublishingSegmentMember_158FFA80B92C016485C663458FD9347A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_12641CCCE6C913C8972063458FD92063" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_3A39293E95A2F770511563458FD9C070" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_12641CCCE6C913C8972063458FD92063" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationDepreciationAndAmortizationDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_D710972A9AE40D5B2F7663458FE3862C" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_B542AD432684CA04DA6B63458FE0C989" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_D710972A9AE40D5B2F7663458FE3862C" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_B542AD432684CA04DA6B63458FE0C989" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_3260561ECC5C6C93217E63458FE0D5EF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_B542AD432684CA04DA6B63458FE0C989" xlink:to="loc_srt_ConsolidationItemsAxis_3260561ECC5C6C93217E63458FE0D5EF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_3260561ECC5C6C93217E63458FE0D5EF" xlink:to="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_3260561ECC5C6C93217E63458FE0D5EF" xlink:to="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_6C3137F63C7B46874F2663458FE14CC6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9" xlink:to="loc_us-gaap_OperatingSegmentsMember_6C3137F63C7B46874F2663458FE14CC6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_2EA60FF23BC283852DEA63458FE2E36F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_EC0F33F68DBF2BCF3F1363458FE137C9" xlink:to="loc_us-gaap_CorporateNonSegmentMember_2EA60FF23BC283852DEA63458FE2E36F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_E1A10B7A20E7E082913863458FE255EC" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_B542AD432684CA04DA6B63458FE0C989" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_E1A10B7A20E7E082913863458FE255EC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_E1A10B7A20E7E082913863458FE255EC" xlink:to="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_E1A10B7A20E7E082913863458FE255EC" xlink:to="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_7B2838A4E0CB39D47BFB63458FE2EF95" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:to="loc_viac_TVEntertainmentSegmentMember_7B2838A4E0CB39D47BFB63458FE2EF95" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_71B76AECD70229A097F463458FE36A37" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:to="loc_viac_CableNetworksSegmentMember_71B76AECD70229A097F463458FE36A37" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_9AD132C18BCCE1AD9BE163458FE30631" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_9AD132C18BCCE1AD9BE163458FE30631" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_B2CF0B26E08E275A35AA63458FE3CDD1" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_52C17F56FD4A40D1252863458FE269AC" xlink:to="loc_viac_PublishingSegmentMember_B2CF0B26E08E275A35AA63458FE3CDD1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="loc_us-gaap_DepreciationAndAmortization_1A97A38213740B773B1063458FE41947" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_D710972A9AE40D5B2F7663458FE3862C" xlink:to="loc_us-gaap_DepreciationAndAmortization_1A97A38213740B773B1063458FE41947" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationLongLivedAssetsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_AB7A42DE26833E1ECE7063458F9F04EC" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A39C42F8FBC0C4AE74C163458F9E9D68" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_AB7A42DE26833E1ECE7063458F9F04EC" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A39C42F8FBC0C4AE74C163458F9E9D68" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_B73DC10405CE9A25039B63458F9EBE82" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A39C42F8FBC0C4AE74C163458F9E9D68" xlink:to="loc_srt_StatementGeographicalAxis_B73DC10405CE9A25039B63458F9EBE82" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_E3A52EFF5032AC8EE75E63458F9EB2E3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_B73DC10405CE9A25039B63458F9EBE82" xlink:to="loc_srt_SegmentGeographicalDomain_E3A52EFF5032AC8EE75E63458F9EB2E3_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_B73DC10405CE9A25039B63458F9EBE82" xlink:to="loc_srt_SegmentGeographicalDomain_E3A52EFF5032AC8EE75E63458F9EB2E3" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_D5E91B321831940BE81663458F9ED0D1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_E3A52EFF5032AC8EE75E63458F9EB2E3" xlink:to="loc_country_US_D5E91B321831940BE81663458F9ED0D1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonUsMember" xlink:label="loc_us-gaap_NonUsMember_B9805D0D159EC7F094FE63458F9F3DF4" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_E3A52EFF5032AC8EE75E63458F9EB2E3" xlink:to="loc_us-gaap_NonUsMember_B9805D0D159EC7F094FE63458F9F3DF4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="loc_us-gaap_NoncurrentAssets_15DD9CCAAE3C71037DA863458F9F395E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_AB7A42DE26833E1ECE7063458F9F04EC" xlink:to="loc_us-gaap_NoncurrentAssets_15DD9CCAAE3C71037DA863458F9F395E" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationOperatingIncomeLossDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CDF4E53323FDD52D837A63458FEF883E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CDF4E53323FDD52D837A63458FEF883E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_66BF7678ABE94B6DDAA563458FF04C88" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CDF4E53323FDD52D837A63458FEF883E" xlink:to="loc_srt_ConsolidationItemsAxis_66BF7678ABE94B6DDAA563458FF04C88" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_66BF7678ABE94B6DDAA563458FF04C88" xlink:to="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_66BF7678ABE94B6DDAA563458FF04C88" xlink:to="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_427172A6438D2ECE374263458FF1EA4F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F" xlink:to="loc_us-gaap_OperatingSegmentsMember_427172A6438D2ECE374263458FF1EA4F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_3973BB27848A71D2A56363458FF11655" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F" xlink:to="loc_us-gaap_CorporateNonSegmentMember_3973BB27848A71D2A56363458FF11655" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MaterialReconcilingItemsMember" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_D45AAA9636815EB1E4E463458FF1B4BA" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3B828CC4FA7FDA21D3F563458FF0281F" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_D45AAA9636815EB1E4E463458FF1B4BA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_793F175FD77996CD95F463458FF15AB6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CDF4E53323FDD52D837A63458FEF883E" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_793F175FD77996CD95F463458FF15AB6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_793F175FD77996CD95F463458FF15AB6" xlink:to="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_793F175FD77996CD95F463458FF15AB6" xlink:to="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_7B8915AA98B41C8F96BB63458FF2FC1D" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:to="loc_viac_TVEntertainmentSegmentMember_7B8915AA98B41C8F96BB63458FF2FC1D" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_D7B3183FF37CEAA047CF63458FF205C0" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:to="loc_viac_CableNetworksSegmentMember_D7B3183FF37CEAA047CF63458FF205C0" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_959A5B547EB961F0FBD263458FF3EE4E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_959A5B547EB961F0FBD263458FF3EE4E" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_EE893FB15D27B817A54563458FF3C5F4" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9BFAD2F811C6B13ACE7963458FF2EE49" xlink:to="loc_viac_PublishingSegmentMember_EE893FB15D27B817A54563458FF3C5F4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AdjustedOperatingIncomeBeforeDepreciationAndAmortization" xlink:label="loc_viac_AdjustedOperatingIncomeBeforeDepreciationAndAmortization_F5FB84311AA35B1B957B63458FF33FE3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_viac_AdjustedOperatingIncomeBeforeDepreciationAndAmortization_F5FB84311AA35B1B957B63458FF33FE3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_48E0FB8DC3906CB7BF3C63458FF3327F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_ShareBasedCompensation_48E0FB8DC3906CB7BF3C63458FF3327F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="loc_us-gaap_DepreciationAndAmortization_4947EF3CB2F52B93F51E63458FF4AD38" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_DepreciationAndAmortization_4947EF3CB2F52B93F51E63458FF4AD38" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesAndOther" xlink:label="loc_viac_RestructuringChargesAndOther_3BED6C4A840810949C5663458FF417F3" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_viac_RestructuringChargesAndOther_3BED6C4A840810949C5663458FF417F3" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ProgrammingCharges" xlink:label="loc_viac_ProgrammingCharges_D6E5406D8A7BC40BD2ED63458FF4E598" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_viac_ProgrammingCharges_D6E5406D8A7BC40BD2ED63458FF4E598" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1_6F7AC3CFD94BD23F0E5163458FF53DCA" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets1_6F7AC3CFD94BD23F0E5163458FF53DCA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_9D67888DC7EA4C89AA8C63458FF5FE21" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_InterestExpense_9D67888DC7EA4C89AA8C63458FF5FE21" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestIncomeOther" xlink:label="loc_us-gaap_InterestIncomeOther_4D882D029EFAF991534563458FF5552D" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_InterestIncomeOther_4D882D029EFAF991534563458FF5552D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:label="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_0773802D21F47E59283463458FF5F576" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_0773802D21F47E59283463458FF5F576" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_C72692836D058DB65E8863458FF5A023" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_C72692836D058DB65E8863458FF5A023" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_18CB52F62E12A06A2F4863458FF54B58" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_18CB52F62E12A06A2F4863458FF54B58" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_D9F09BD9B171B13A141263458FF6DD20" xlink:type="locator"/>

<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_D9F09BD9B171B13A141263458FF6DD20" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_A11E2CC6D6733FE61BDB63458FF6A72B" xlink:type="locator"/>

<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_A11E2CC6D6733FE61BDB63458FF6A72B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_C4A4226B90DBF31DDD3F63458FF67006" xlink:type="locator"/>

<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_C4A4226B90DBF31DDD3F63458FF67006" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_FA1B4B0FA629CB8DE5FB63458FF714B1" xlink:type="locator"/>

<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_FA1B4B0FA629CB8DE5FB63458FF714B1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_386CAFC87AD8F0B1856263458FF7A1AD" xlink:type="locator"/>

<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_386CAFC87AD8F0B1856263458FF7A1AD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_3EE5B7BAA9AACEAAF4E063458FF7895D" xlink:type="locator"/>

<link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_3EE5B7BAA9AACEAAF4E063458FF7895D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:label="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_57F75C02D611A23145F163458FF7FECA" xlink:type="locator"/>

<link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_57F75C02D611A23145F163458FF7FECA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_23B38B81EEC255606C6463458FF7A0FD" xlink:type="locator"/>

<link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_ProfitLoss_23B38B81EEC255606C6463458FF7A0FD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_93327231FDDD8329A48863458FF8F997" xlink:type="locator"/>

<link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_93327231FDDD8329A48863458FF8F997" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_065751E635454A3277A563458FF8DD86" xlink:type="locator"/>

<link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ADE89F2D5951BB841EED63458FF36E18" xlink:to="loc_us-gaap_NetIncomeLoss_065751E635454A3277A563458FF8DD86" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationRevenueByTypeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_C3C8CEE21E4250A191DB63458FBA1496" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_4E26ACB54B12C587832563458FB6EECA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_C3C8CEE21E4250A191DB63458FBA1496" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_4E26ACB54B12C587832563458FB6EECA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_B4E14F2B6E4B3843C26663458FB6ACD1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_4E26ACB54B12C587832563458FB6EECA" xlink:to="loc_srt_ProductOrServiceAxis_B4E14F2B6E4B3843C26663458FB6ACD1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_B4E14F2B6E4B3843C26663458FB6ACD1" xlink:to="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_B4E14F2B6E4B3843C26663458FB6ACD1" xlink:to="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdvertisingMember" xlink:label="loc_us-gaap_AdvertisingMember_3EBEB44FFF775A00AE7463458FB79475" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_us-gaap_AdvertisingMember_3EBEB44FFF775A00AE7463458FB79475" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AffiliateMember" xlink:label="loc_viac_AffiliateMember_938D26F9B7883C9E2B6B63458FB79024" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_viac_AffiliateMember_938D26F9B7883C9E2B6B63458FB79024" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ContentLicensingMember" xlink:label="loc_viac_ContentLicensingMember_F4DFC910550E6ABD7B7A63458FB8493C" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_viac_ContentLicensingMember_F4DFC910550E6ABD7B7A63458FB8493C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TheatricalMember" xlink:label="loc_viac_TheatricalMember_4DF41B5C9325DD5C1BF163458FB858BD" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_viac_TheatricalMember_4DF41B5C9325DD5C1BF163458FB858BD" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_495F71B3829864386A0663458FB83BB0" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_viac_PublishingSegmentMember_495F71B3829864386A0663458FB83BB0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ServiceOtherMember" xlink:label="loc_us-gaap_ServiceOtherMember_B9DF4E8E8ADDC422D41063458FB8F91C" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8114561F392B878C58A563458FB6E159" xlink:to="loc_us-gaap_ServiceOtherMember_B9DF4E8E8ADDC422D41063458FB8F91C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_FD3E56C36085FFD024C963458FB8AE0B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_4E26ACB54B12C587832563458FB6EECA" xlink:to="loc_srt_StatementGeographicalAxis_FD3E56C36085FFD024C963458FB8AE0B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_FD3E56C36085FFD024C963458FB8AE0B" xlink:to="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_FD3E56C36085FFD024C963458FB8AE0B" xlink:to="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_07A37E64BB192673A68263458FB9BE3A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7" xlink:to="loc_country_US_07A37E64BB192673A68263458FB9BE3A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonUsMember" xlink:label="loc_us-gaap_NonUsMember_FF3BF0BC9B3CD7FB1BBA63458FB93E14" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_E27D3A1CBC3633B16E4863458FB9F7A7" xlink:to="loc_us-gaap_NonUsMember_FF3BF0BC9B3CD7FB1BBA63458FB93E14" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1998A03BD581503B232C63458FBAFF40" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_C3C8CEE21E4250A191DB63458FBA1496" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1998A03BD581503B232C63458FBAFF40" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationRevenuesDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2038416795DFBF61FFDD6345900B3A08" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_69FC2B6926DBD76647BF634590059B8C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2038416795DFBF61FFDD6345900B3A08" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_69FC2B6926DBD76647BF634590059B8C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_FEE8F559DF1C5F3F1F1E634590059C7A" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_69FC2B6926DBD76647BF634590059B8C" xlink:to="loc_srt_ConsolidationItemsAxis_FEE8F559DF1C5F3F1F1E634590059C7A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_FEE8F559DF1C5F3F1F1E634590059C7A" xlink:to="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_FEE8F559DF1C5F3F1F1E634590059C7A" xlink:to="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_828FF2F8D8184332F4AC634590065124" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E" xlink:to="loc_us-gaap_OperatingSegmentsMember_828FF2F8D8184332F4AC634590065124" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CorporateAndEliminationsMember" xlink:label="loc_viac_CorporateAndEliminationsMember_0B7B7473D3AE00E8DA3263459006BF66" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E" xlink:to="loc_viac_CorporateAndEliminationsMember_0B7B7473D3AE00E8DA3263459006BF66" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IntersegmentEliminationMember" xlink:label="loc_us-gaap_IntersegmentEliminationMember_8E02DC72C5311EE1C449634590070526" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_E415BAF6710705E95F8963459005DA3E" xlink:to="loc_us-gaap_IntersegmentEliminationMember_8E02DC72C5311EE1C449634590070526" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_74FB18F2E1454F8B2827634590070760" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_69FC2B6926DBD76647BF634590059B8C" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_74FB18F2E1454F8B2827634590070760" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_74FB18F2E1454F8B2827634590070760" xlink:to="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_74FB18F2E1454F8B2827634590070760" xlink:to="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TVEntertainmentSegmentMember" xlink:label="loc_viac_TVEntertainmentSegmentMember_8EB4B7DC0BD37BDD3FD363459007B389" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:to="loc_viac_TVEntertainmentSegmentMember_8EB4B7DC0BD37BDD3FD363459007B389" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CableNetworksSegmentMember" xlink:label="loc_viac_CableNetworksSegmentMember_1D3764A566BFFF93684C63459007F60A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:to="loc_viac_CableNetworksSegmentMember_1D3764A566BFFF93684C63459007F60A" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_FilmedEntertainmentSegmentMember" xlink:label="loc_viac_FilmedEntertainmentSegmentMember_F6DB63D0B8AE2661EAE1634590084065" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:to="loc_viac_FilmedEntertainmentSegmentMember_F6DB63D0B8AE2661EAE1634590084065" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_PublishingSegmentMember" xlink:label="loc_viac_PublishingSegmentMember_3046C4EF27048947A5E86345900856BD" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9A641CFDC9B0CF8C14C463459007EDCB" xlink:to="loc_viac_PublishingSegmentMember_3046C4EF27048947A5E86345900856BD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_37E893CFABCF98D294216345900884D6" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_69FC2B6926DBD76647BF634590059B8C" xlink:to="loc_srt_ProductOrServiceAxis_37E893CFABCF98D294216345900884D6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_37E893CFABCF98D294216345900884D6" xlink:to="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_37E893CFABCF98D294216345900884D6" xlink:to="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdvertisingMember" xlink:label="loc_us-gaap_AdvertisingMember_DBFA44F1EE57948B05FD63459009D119" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_us-gaap_AdvertisingMember_DBFA44F1EE57948B05FD63459009D119" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_AffiliateMember" xlink:label="loc_viac_AffiliateMember_BB5176FFC6DBD54EABD463459009C3F7" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_viac_AffiliateMember_BB5176FFC6DBD54EABD463459009C3F7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ContentLicensingMember" xlink:label="loc_viac_ContentLicensingMember_35EBF78A3784C6D65D5163459009026F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_viac_ContentLicensingMember_35EBF78A3784C6D65D5163459009026F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ServiceOtherMember" xlink:label="loc_us-gaap_ServiceOtherMember_4A4287C54E0192ED529C6345900A3B14" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_us-gaap_ServiceOtherMember_4A4287C54E0192ED529C6345900A3B14" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_TheatricalMember" xlink:label="loc_viac_TheatricalMember_D84E1B9B4E9BB269D3E66345900A2023" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_viac_TheatricalMember_D84E1B9B4E9BB269D3E66345900A2023" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_HomeEntertainmentMember" xlink:label="loc_viac_HomeEntertainmentMember_2F44691DAA4D7515ACA76345900A7EBE" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_viac_HomeEntertainmentMember_2F44691DAA4D7515ACA76345900A7EBE" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_LicensingMember" xlink:label="loc_viac_LicensingMember_4D61F9AE1280228002246345900A5D71" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_DDFEF0CB810794BE327A63459009E7E4" xlink:to="loc_viac_LicensingMember_4D61F9AE1280228002246345900A5D71" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_F6C01370DA024F19183C6345900BE478" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2038416795DFBF61FFDD6345900B3A08" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_F6C01370DA024F19183C6345900BE478" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SegmentAndRevenueInformationTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensation" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationExpenseDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_E4DADEF0ACD45CCA0E96634591E3F1B9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_E4DADEF0ACD45CCA0E96634591E3F1B9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2E2D8207E824A643212E634591E41897_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E4DADEF0ACD45CCA0E96634591E3F1B9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2E2D8207E824A643212E634591E41897_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2E2D8207E824A643212E634591E41897" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E4DADEF0ACD45CCA0E96634591E3F1B9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2E2D8207E824A643212E634591E41897" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_59A906BF1D2163370C53634591E40289" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2E2D8207E824A643212E634591E41897" xlink:to="loc_viac_ViacomIncMember_59A906BF1D2163370C53634591E40289" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_109921EB797C3FFE3BF0634591E5AADC" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:to="loc_us-gaap_StatementClassOfStockAxis_109921EB797C3FFE3BF0634591E5AADC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3672EC4034E51F7E5848634591E52978_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_109921EB797C3FFE3BF0634591E5AADC" xlink:to="loc_us-gaap_ClassOfStockDomain_3672EC4034E51F7E5848634591E52978_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3672EC4034E51F7E5848634591E52978" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_109921EB797C3FFE3BF0634591E5AADC" xlink:to="loc_us-gaap_ClassOfStockDomain_3672EC4034E51F7E5848634591E52978" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_B130551786B15DC39683634591E56A22" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3672EC4034E51F7E5848634591E52978" xlink:to="loc_us-gaap_CommonClassBMember_B130551786B15DC39683634591E56A22" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_957855BFB063C5870824634591E61B68" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_957855BFB063C5870824634591E61B68" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_957855BFB063C5870824634591E61B68" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_957855BFB063C5870824634591E61B68" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_B5727BAD5A4A388918BF634591E62DB6" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_B5727BAD5A4A388918BF634591E62DB6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestructuringChargesAndOtherMember" xlink:label="loc_viac_RestructuringChargesAndOtherMember_5EE754F191B02887B097634591E7EA4E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_3BCB18565C3D3D125A41634591E62C89" xlink:to="loc_viac_RestructuringChargesAndOtherMember_5EE754F191B02887B097634591E7EA4E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srt_TitleOfIndividualAxis_89018B64E6109D0BDBBC634591E72F9D" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B0E1B416C98B2854D074634591E367EA" xlink:to="loc_srt_TitleOfIndividualAxis_89018B64E6109D0BDBBC634591E72F9D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_816CF5E8BDE6EA36E9AC634591E712F8_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_89018B64E6109D0BDBBC634591E72F9D" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_816CF5E8BDE6EA36E9AC634591E712F8_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_89018B64E6109D0BDBBC634591E72F9D" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_816CF5E8BDE6EA36E9AC634591E712F8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ManagementMember" xlink:label="loc_srt_ManagementMember_A6C43EEEC6810769F8DD634591E78B4B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_816CF5E8BDE6EA36E9AC634591E712F8" xlink:to="loc_srt_ManagementMember_A6C43EEEC6810769F8DD634591E78B4B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_43A446645BBD75CB77B8634591E8F2CC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_43A446645BBD75CB77B8634591E8F2CC" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio" xlink:label="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_452234DBEEA0793F347E634591E8654D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_452234DBEEA0793F347E634591E8654D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedStockExpense" xlink:label="loc_us-gaap_RestrictedStockExpense_196FBDB9B152BA4FDB43634591E95BCB" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_RestrictedStockExpense_196FBDB9B152BA4FDB43634591E95BCB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockOptionPlanExpense" xlink:label="loc_us-gaap_StockOptionPlanExpense_3C3A263F61800B1BDED7634591E99FBC" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_StockOptionPlanExpense_3C3A263F61800B1BDED7634591E99FBC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_0A850304C74FE5C72101634591E93C9E" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_ShareBasedCompensation_0A850304C74FE5C72101634591E93C9E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_89E4E709BB8977009737634591E9560F" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_89E4E709BB8977009737634591E9560F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_B43E4A12597AE4911FC5634591E9FC58" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_B43E4A12597AE4911FC5634591E9FC58" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockBasedCompensationForfeitures" xlink:label="loc_viac_StockBasedCompensationForfeitures_25BE11199D148774F6B5634591EA3736" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_viac_StockBasedCompensationForfeitures_25BE11199D148774F6B5634591EA3736" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockBasedCompensationExpenseAccelerations" xlink:label="loc_viac_StockBasedCompensationExpenseAccelerations_1328B693966A8B404F1D634591EA7E75" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_69F09DAE1DAF1E2CF901634591E83555" xlink:to="loc_viac_StockBasedCompensationExpenseAccelerations_1328B693966A8B404F1D634591EA7E75" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationRsusAndPsusDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7194EA064C61C7C3310634591CD29F3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7194EA064C61C7C3310634591CD29F3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_4CE0AA40F7A9D0DC54EA634591CEBF01" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7194EA064C61C7C3310634591CD29F3" xlink:to="loc_us-gaap_AwardTypeAxis_4CE0AA40F7A9D0DC54EA634591CEBF01" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4CE0AA40F7A9D0DC54EA634591CEBF01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410_default" xlink:type="arc"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4CE0AA40F7A9D0DC54EA634591CEBF01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_RestrictedStockUnitsandPerformanceShareUnitsMember" xlink:label="loc_viac_RestrictedStockUnitsandPerformanceShareUnitsMember_4FFB754A16B69124DDEB634591CF366C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410" xlink:to="loc_viac_RestrictedStockUnitsandPerformanceShareUnitsMember_4FFB754A16B69124DDEB634591CF366C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_2813D6D42679F2942FB4634591CFD6B5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_2813D6D42679F2942FB4634591CFD6B5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:label="loc_us-gaap_PerformanceSharesMember_E94B5BF23F0BFA14384D634591CF4B50" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB6CAB3D692D6A0ACFBE634591CE2410" xlink:to="loc_us-gaap_PerformanceSharesMember_E94B5BF23F0BFA14384D634591CF4B50" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_50DAA5D44B9B7CD8CD73634591CFF2B6" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7194EA064C61C7C3310634591CD29F3" xlink:to="loc_srt_RangeAxis_50DAA5D44B9B7CD8CD73634591CFF2B6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_50DAA5D44B9B7CD8CD73634591CFF2B6" xlink:to="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_50DAA5D44B9B7CD8CD73634591CFF2B6" xlink:to="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_224DD3F8ABCAEC41DB47634591D077EF" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102" xlink:to="loc_srt_MinimumMember_224DD3F8ABCAEC41DB47634591D077EF" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_14FBBC02A2E2C6B9872E634591D0B52E" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_EACF7C0A14835087638E634591CFA102" xlink:to="loc_srt_MaximumMember_14FBBC02A2E2C6B9872E634591D0B52E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_3F7A56CABB5EC5F43F42634591D132F8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_3F7A56CABB5EC5F43F42634591D132F8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_B707E3DE0E67F7FFAF69634591D1EE43" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_B707E3DE0E67F7FFAF69634591D1EE43" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_AFBAE39539CA938F7984634591D1A997" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_AFBAE39539CA938F7984634591D1A997" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_E7AD27737F75E22AF629634591D17B10" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_E7AD27737F75E22AF629634591D17B10" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantedInPeriodFairValue" xlink:label="loc_viac_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantedInPeriodFairValue_1AC2FCA54DFD30E3F809634591D22F52" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_viac_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantedInPeriodFairValue_1AC2FCA54DFD30E3F809634591D22F52" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_067A548361002A428C0B634591D2D61C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_067A548361002A428C0B634591D2D61C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1961F1CCBED90FE5D1F3634591D30489" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1961F1CCBED90FE5D1F3634591D30489" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5C140B9D3434A8E08E8A634591D33B0E" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5C140B9D3434A8E08E8A634591D33B0E" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_68A09E87591ACF6A05BD634591D360FA" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_03D46D8C6B52A8B256D7634591D245FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_68A09E87591ACF6A05BD634591D360FA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4CACEEE546F2DC1B876C634591D12F54" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_69CDBBE51DE22EF33FD7634591D4F578" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_69CDBBE51DE22EF33FD7634591D4F578" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_F6621AD732E74F959262634591D4C168" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_F6621AD732E74F959262634591D4C168" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_62ADA68DE3A2F5E412A3634591D49E39" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_62ADA68DE3A2F5E412A3634591D49E39" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_400D84BB71B427BD01F8634591D55DC8" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6B3D1236A6DA7165926A634591D346CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_400D84BB71B427BD01F8634591D55DC8" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationStockOptionsBlackScholesAssumptionsDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_08C44A50735150A2472C634591AB005F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_08C44A50735150A2472C634591AB005F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2E1E9BE51852FABC9FFD634591ABB4A3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_08C44A50735150A2472C634591AB005F" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2E1E9BE51852FABC9FFD634591ABB4A3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D4237310311BAE8BA955634591ABEEF1_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2E1E9BE51852FABC9FFD634591ABB4A3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D4237310311BAE8BA955634591ABEEF1_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D4237310311BAE8BA955634591ABEEF1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2E1E9BE51852FABC9FFD634591ABB4A3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D4237310311BAE8BA955634591ABEEF1" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_0350E751925355819A21634591AC4B64" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D4237310311BAE8BA955634591ABEEF1" xlink:to="loc_viac_ViacomIncMember_0350E751925355819A21634591AC4B64" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_576628E36183D6BEED2D634591AC70C5" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_08C44A50735150A2472C634591AB005F" xlink:to="loc_us-gaap_StatementClassOfStockAxis_576628E36183D6BEED2D634591AC70C5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_F855FE7AB5F128FA9CD2634591AC9CB1_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_576628E36183D6BEED2D634591AC70C5" xlink:to="loc_us-gaap_ClassOfStockDomain_F855FE7AB5F128FA9CD2634591AC9CB1_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_F855FE7AB5F128FA9CD2634591AC9CB1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_576628E36183D6BEED2D634591AC70C5" xlink:to="loc_us-gaap_ClassOfStockDomain_F855FE7AB5F128FA9CD2634591AC9CB1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_82C3628BB2789BC03177634591AD6DAC" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_F855FE7AB5F128FA9CD2634591AC9CB1" xlink:to="loc_us-gaap_CommonClassBMember_82C3628BB2789BC03177634591AD6DAC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_5BDB44610C2A6A829D01634591AD25F7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_5BDB44610C2A6A829D01634591AD25F7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_10B3EC0F8E2C2CDC0BF5634591AE1E6B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_10B3EC0F8E2C2CDC0BF5634591AE1E6B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_939ECC2942F02A0C893F634591AE15E7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_939ECC2942F02A0C893F634591AE15E7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_6BFB3AC483637B3FB19E634591AEB530" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7A44A76F223E2088A1B1634591ADF0A4" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_6BFB3AC483637B3FB19E634591AEB530" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationStockOptionsNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_6F1B309FB04CDE6FD9E6634591B8E54B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_6F1B309FB04CDE6FD9E6634591B8E54B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9314595229423A04AF69634591B98938_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6F1B309FB04CDE6FD9E6634591B8E54B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9314595229423A04AF69634591B98938_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9314595229423A04AF69634591B98938" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6F1B309FB04CDE6FD9E6634591B8E54B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9314595229423A04AF69634591B98938" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_184A932EC7365A2DF160634591B9630B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9314595229423A04AF69634591B98938" xlink:to="loc_viac_ViacomIncMember_184A932EC7365A2DF160634591B9630B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_9D713BBB027BC4B31D1B634591BA6F8C" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:to="loc_us-gaap_StatementClassOfStockAxis_9D713BBB027BC4B31D1B634591BA6F8C" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_F47E8DFAD4AF08FA70A3634591BA31D4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9D713BBB027BC4B31D1B634591BA6F8C" xlink:to="loc_us-gaap_ClassOfStockDomain_F47E8DFAD4AF08FA70A3634591BA31D4_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_F47E8DFAD4AF08FA70A3634591BA31D4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9D713BBB027BC4B31D1B634591BA6F8C" xlink:to="loc_us-gaap_ClassOfStockDomain_F47E8DFAD4AF08FA70A3634591BA31D4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_FC5F88AACB442A4544FE634591BA48CD" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_F47E8DFAD4AF08FA70A3634591BA31D4" xlink:to="loc_us-gaap_CommonClassBMember_FC5F88AACB442A4544FE634591BA48CD" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_F2F2DD26BB028FF549C3634591BB17C0" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:to="loc_us-gaap_AwardTypeAxis_F2F2DD26BB028FF549C3634591BB17C0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1293A3CF958D94F04569634591BB509F_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_F2F2DD26BB028FF549C3634591BB17C0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1293A3CF958D94F04569634591BB509F_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1293A3CF958D94F04569634591BB509F" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_F2F2DD26BB028FF549C3634591BB17C0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1293A3CF958D94F04569634591BB509F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_F97ACF6DE7655470A2D1634591BB1ACA" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1293A3CF958D94F04569634591BB509F" xlink:to="loc_us-gaap_EmployeeStockOptionMember_F97ACF6DE7655470A2D1634591BB1ACA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_27A790F1C4D1F8478471634591BCB37F" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_CE9D46A84C6DDBB74EB4634591B82B1C" xlink:to="loc_srt_RangeAxis_27A790F1C4D1F8478471634591BCB37F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_27A790F1C4D1F8478471634591BCB37F" xlink:to="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_27A790F1C4D1F8478471634591BCB37F" xlink:to="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_BA775874EA7D0F8A1308634591BD44B9" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1" xlink:to="loc_srt_MinimumMember_BA775874EA7D0F8A1308634591BD44B9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_B8AC87581BF7862E39AE634591BDD45B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_44E8D4296399151CE31D634591BC03C1" xlink:to="loc_srt_MaximumMember_B8AC87581BF7862E39AE634591BDD45B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_B37EE83390CAE50A43C7634591BD1188" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_B37EE83390CAE50A43C7634591BD1188" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_10DCA31AFDBBD500BEFE634591BE90E9" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_10DCA31AFDBBD500BEFE634591BE90E9" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_0D9DBB7E50F7AC2310B6634591BE8218" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_0D9DBB7E50F7AC2310B6634591BE8218" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsMinimumExpectedTermOfCompanyOption" xlink:label="loc_viac_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsMinimumExpectedTermOfCompanyOption_0566C120CAB886D89977634591BE1181" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_viac_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsMinimumExpectedTermOfCompanyOption_0566C120CAB886D89977634591BE1181" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_55E4F023EEFE544BDE30634591BFE2B6" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_55E4F023EEFE544BDE30634591BFE2B6" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_98F1E4C78A4325DC420C634591BF50EB" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_98F1E4C78A4325DC420C634591BF50EB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_EE4BEC5F9DF07B386D40634591BFAC61" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_EE4BEC5F9DF07B386D40634591BFAC61" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_AB8BD047F632483C6F81634591BFB2C4" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_SharePrice_AB8BD047F632483C6F81634591BFB2C4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_11E590E1EFA64D4E9347634591BF1095" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_11E590E1EFA64D4E9347634591BF1095" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_55DEC0BCA4E0BA1ABF3A634591C065C4" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_55DEC0BCA4E0BA1ABF3A634591C065C4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_BAC6084A5025052FD26F634591C0AA4E" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C271F13B94E435C0633D634591BD7EA1" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_BAC6084A5025052FD26F634591C0AA4E" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationStockOptionsOtherInformationDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationStockOptionsRollforwardDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockBasedCompensationTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockholdersEquity" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockholdersEquityAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_D2A72B9AE8F504CA580063459202AE81" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_4F8D34D0B582B2BE3FF5634591FF217B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_D2A72B9AE8F504CA580063459202AE81" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_4F8D34D0B582B2BE3FF5634591FF217B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_0196C08AC2EACA48089B63459200FA79" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_4F8D34D0B582B2BE3FF5634591FF217B" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_0196C08AC2EACA48089B63459200FA79" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0196C08AC2EACA48089B63459200FA79" xlink:to="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0196C08AC2EACA48089B63459200FA79" xlink:to="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_75F00F84147A47A40CF363459201D033" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_75F00F84147A47A40CF363459201D033" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_5A160FC2680BB05F140B63459201CE59" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_5A160FC2680BB05F140B63459201CE59" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_04B303BFB870470C5A8363459201E427" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_04B303BFB870470C5A8363459201E427" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_82C743B1A6B04936365363459201DE32" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5D3B527DC78C9B26CE636345920030FB" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_82C743B1A6B04936365363459201DE32" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_D2A72B9AE8F504CA580063459202AE81" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_D1B19E80F273B42E3B0F63459202EC84" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_D1B19E80F273B42E3B0F63459202EC84" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_3E2CC0C3D04E28E7B43563459202410B" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_3E2CC0C3D04E28E7B43563459202410B" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_E801D13D51833DF78AC763459203C1E0" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_E801D13D51833DF78AC763459203C1E0" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_B832A40BD161439C088963459203DFA5" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_B832A40BD161439C088963459203DFA5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_95A1D309A6B530EA49596345920319CE" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_95A1D309A6B530EA49596345920319CE" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect_2D37D9879F1E7754169F634592042E04" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_9035B33FFE0FFDD69AA3634592023C24" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect_2D37D9879F1E7754169F634592042E04" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_7D853E08D8B5EB2DABD2634592045006" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_D2A72B9AE8F504CA580063459202AE81" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_7D853E08D8B5EB2DABD2634592045006" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_DBC45CEB3026A0D5271663459204FE47" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_D2A72B9AE8F504CA580063459202AE81" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_DBC45CEB3026A0D5271663459204FE47" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockholdersEquityNarrativeDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_ADEA9924E920CAC1626A63459211F263" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_ADEA9924E920CAC1626A63459211F263" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E780738C17E97AAEFC463459211FA0C_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ADEA9924E920CAC1626A63459211F263" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E780738C17E97AAEFC463459211FA0C_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E780738C17E97AAEFC463459211FA0C" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ADEA9924E920CAC1626A63459211F263" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E780738C17E97AAEFC463459211FA0C" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_6CCBCF416E38043D308D634592112246" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E780738C17E97AAEFC463459211FA0C" xlink:to="loc_viac_ViacomIncMember_6CCBCF416E38043D308D634592112246" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2320B31F3EFC4F2A93C663459212464A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:to="loc_dei_LegalEntityAxis_2320B31F3EFC4F2A93C663459212464A" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2320B31F3EFC4F2A93C663459212464A" xlink:to="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7_default" xlink:type="arc"/>

<link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2320B31F3EFC4F2A93C663459212464A" xlink:to="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSMember" xlink:label="loc_viac_CBSMember_9E05554277F4DD823CD1634592130780" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7" xlink:to="loc_viac_CBSMember_9E05554277F4DD823CD1634592130780" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_ViacomIncMember" xlink:label="loc_viac_ViacomIncMember_2747BFAA2C7CD66F9EA463459213945A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_686E5D059078D7EF7FAA6345921215C7" xlink:to="loc_viac_ViacomIncMember_2747BFAA2C7CD66F9EA463459213945A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_48CA2A5A34A2B9F34FB6634592131EB7" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:to="loc_us-gaap_StatementClassOfStockAxis_48CA2A5A34A2B9F34FB6634592131EB7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_48CA2A5A34A2B9F34FB6634592131EB7" xlink:to="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_48CA2A5A34A2B9F34FB6634592131EB7" xlink:to="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_E7C03954E4C54BD633BF634592149510" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3" xlink:to="loc_us-gaap_CommonClassAMember_E7C03954E4C54BD633BF634592149510" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_A4B6A86A3E4C5002198963459214DF8F" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3" xlink:to="loc_us-gaap_CommonClassBMember_A4B6A86A3E4C5002198963459214DF8F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_5B2B05DFFC5353473160634592141F7F" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_59E777243DA885DB8B6F6345921374C3" xlink:to="loc_us-gaap_CommonStockMember_5B2B05DFFC5353473160634592141F7F" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_77AEA51DF1775573A01E63459214D0CB" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD1C9D175DB72255E95863459211D005" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_77AEA51DF1775573A01E63459214D0CB" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1E7578E5A7FAAC7F7387634592152BA5_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_77AEA51DF1775573A01E63459214D0CB" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1E7578E5A7FAAC7F7387634592152BA5_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1E7578E5A7FAAC7F7387634592152BA5" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_77AEA51DF1775573A01E63459214D0CB" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1E7578E5A7FAAC7F7387634592152BA5" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_0D15F57225AA50F1087263459215A13B" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_1E7578E5A7FAAC7F7387634592152BA5" xlink:to="loc_us-gaap_SubsequentEventMember_0D15F57225AA50F1087263459215A13B" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio" xlink:label="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_A465C544C812D75A613B63459216B154" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_viac_BusinessCombinationEquityInterestIssuedOrIssuableShareConversionRatio_A465C544C812D75A613B63459216B154" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_74C5ABDF659929AD05FA63459216FFB1" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_74C5ABDF659929AD05FA63459216FFB1" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_3AE882C914781BE7C3B76345921630AC" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_3AE882C914781BE7C3B76345921630AC" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_49532CAE0E098B53A9CA634592162422" xlink:type="locator"/>

<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_49532CAE0E098B53A9CA634592162422" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_0B4A6C31CB004FD8D49063459217DBE4" xlink:type="locator"/>

<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_DividendsCommonStockCash_0B4A6C31CB004FD8D49063459217DBE4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_A1B75205258AAEBB439263459217BDC4" xlink:type="locator"/>

<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_A1B75205258AAEBB439263459217BDC4" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_D65D9A3D8246D11D70AB634592176C45" xlink:type="locator"/>

<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_D65D9A3D8246D11D70AB634592176C45" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_626692DD10DADB7A34AB63459217D1E8" xlink:type="locator"/>

<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_626692DD10DADB7A34AB63459217D1E8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_D44D0EBF6B24933C6A7C634592186F95" xlink:type="locator"/>

<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_D44D0EBF6B24933C6A7C634592186F95" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_MinimumClassASharesForConversion" xlink:label="loc_viac_MinimumClassASharesForConversion_37DF5F1C97D7649374A4634592188AA7" xlink:type="locator"/>

<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_viac_MinimumClassASharesForConversion_37DF5F1C97D7649374A4634592188AA7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_6B8C49FAE441121F9345634592189796" xlink:type="locator"/>

<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_592C0D47FD44F6D389BA63459215702A" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_6B8C49FAE441121F9345634592189796" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/StockholdersEquityTables" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SupplementalFinancialInformation" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SupplementalFinancialInformationComponentsOfOtherItemsNetDetails" xlink:type="extended"/>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SupplementalFinancialInformationSupplementalCashFlowInformationDetails" xlink:type="extended">

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsLineItems" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_A4DCCDB175E8900A70A7638D74DFD29D" xlink:type="locator"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_6B1AFFE772FB1082CAF8638D74DCD6BB" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_A4DCCDB175E8900A70A7638D74DFD29D" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_6B1AFFE772FB1082CAF8638D74DCD6BB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4AC9B06504526ED500A1638D74DCB850" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_6B1AFFE772FB1082CAF8638D74DCD6BB" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4AC9B06504526ED500A1638D74DCB850" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4AC9B06504526ED500A1638D74DCB850" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_4AC9B06504526ED500A1638D74DCB850" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentContinuingOperationsMember" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_4E1EF3942D6CCB8BA7C0638D74DDF7D3" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_4E1EF3942D6CCB8BA7C0638D74DDF7D3" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_58CA97AA3522F2B7BF9B638D74DD4DAA" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_8370D941627E20C41385638D74DD4DE7" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_58CA97AA3522F2B7BF9B638D74DD4DAA" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_DDAA846121183FE8CD02638D74DD576A" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_6B1AFFE772FB1082CAF8638D74DCD6BB" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_DDAA846121183FE8CD02638D74DD576A" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_00A41881ED665963FC14638D74DD7267_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DDAA846121183FE8CD02638D74DD576A" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_00A41881ED665963FC14638D74DD7267_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_00A41881ED665963FC14638D74DD7267" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DDAA846121183FE8CD02638D74DD576A" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_00A41881ED665963FC14638D74DD7267" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_99B5D4FAC38407290C09638D74DEFDB8" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_00A41881ED665963FC14638D74DD7267" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_99B5D4FAC38407290C09638D74DEFDB8" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_C9689CD18FAB6F4BFA23638D74DF6642" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_6B1AFFE772FB1082CAF8638D74DCD6BB" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_C9689CD18FAB6F4BFA23638D74DF6642" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_CC9FDAAEEDED6EE52AC7638D74DF61A4_default" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_C9689CD18FAB6F4BFA23638D74DF6642" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_CC9FDAAEEDED6EE52AC7638D74DF61A4_default" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_CC9FDAAEEDED6EE52AC7638D74DF61A4" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_C9689CD18FAB6F4BFA23638D74DF6642" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_CC9FDAAEEDED6EE52AC7638D74DF61A4" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_CBSRadioMember" xlink:label="loc_viac_CBSRadioMember_2A35888D068770BD1F27638D74DF0B76" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_CC9FDAAEEDED6EE52AC7638D74DF61A4" xlink:to="loc_viac_CBSRadioMember_2A35888D068770BD1F27638D74DF0B76" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="loc_us-gaap_InterestPaidNet_69050E72425F70E9616C638D74DF4D72" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_A4DCCDB175E8900A70A7638D74DFD29D" xlink:to="loc_us-gaap_InterestPaidNet_69050E72425F70E9616C638D74DF4D72" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_C01ECC766AA0ADD3EF52638D74E0FA3D" xlink:type="locator"/>

<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_A4DCCDB175E8900A70A7638D74DFD29D" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_C01ECC766AA0ADD3EF52638D74E0FA3D" xlink:type="arc"/>

<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:label="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_B648DB4C90F1B04CAA64638D74E0C5B6" xlink:type="locator"/>

<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_A4DCCDB175E8900A70A7638D74DFD29D" xlink:to="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_B648DB4C90F1B04CAA64638D74E0C5B6" xlink:type="arc"/>

<link:loc xlink:href="viac-20191231.xsd#viac_StockholdersEquityNoteSplitOffTransaction" xlink:label="loc_viac_StockholdersEquityNoteSplitOffTransaction_965A534B748D9EFA98EB638D74E06E11" xlink:type="locator"/>

<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_B648DB4C90F1B04CAA64638D74E0C5B6" xlink:to="loc_viac_StockholdersEquityNoteSplitOffTransaction_965A534B748D9EFA98EB638D74E06E11" xlink:type="arc"/>

</link:definitionLink>

<link:definitionLink xlink:role="http://www.viacbs.com/role/SupplementalFinancialInformationTables" xlink:type="extended"/>

</link:linkbase>

8 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 3/28/22  Paramount Global                  424B2                  2:611K                                   Donnelley … Solutions/FA
 3/24/22  Paramount Global                  424B3                  1:561K                                   Donnelley … Solutions/FA
 2/15/22  Paramount Global                  10-K       12/31/21  163:23M
 3/25/21  Paramount Global                  424B5                  1:890K                                   Donnelley … Solutions/FA
 3/25/21  Paramount Global                  424B5                  1:628K                                   Donnelley … Solutions/FA
 3/22/21  Paramount Global                  424B5                  1:853K                                   Donnelley … Solutions/FA
 3/22/21  Paramount Global                  424B5                  1:599K                                   Donnelley … Solutions/FA
 2/24/21  Paramount Global                  10-K       12/31/20  170:25M

↑Top

Filing Submission 0000813828-20-000013 – Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

ViacomCBS Inc. – ‘10-K’ for 12/31/19 – ‘EX-101.DEF’

On: Thursday, 2/20/20, at 5:33pm ET · For: 12/31/19 · Accession #: 813828-20-13 · File #: 1-09553

Annual Report — Form 10-K — Sect. 13 / 15(d) – SEA’34Filing Table of Contents

‘EX-101.DEF’ — XBRL Definitions — viac-20191231_def

This Exhibit is an XBRL XML File.

8 Subsequent Filings that Reference this Filing

Annual Report — Form 10-K — Sect. 13 / 15(d) – SEA’34
Filing Table of Contents