SEC Info℠  
    Home      Search      My Interests      Help      Sign In      Please Sign In

Kratos Defense & Security Solutions, Inc. – ‘10-Q’ for 6/26/22 – ‘EX-101.DEF’

On:  Thursday, 8/4/22, at 4:18pm ET   ·   For:  6/26/22   ·   Accession #:  1069258-22-54   ·   File #:  1-34460

Previous ‘10-Q’:  ‘10-Q’ on 5/5/22 for 3/27/22   ·   Next:  ‘10-Q’ on 11/3/22 for 9/25/22   ·   Latest:  ‘10-Q/A’ on 2/21/24 for 3/26/23   ·   5 References:   

Find Words in Filings emoji
 		  in    Show  and   ↓Hints

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

 8/04/22  Kratos Defense & Sec Solutio… Inc 10-Q        6/26/22   76:8M

Quarterly Report   —   Form 10-Q

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML   1.65M 
 2: EX-10.1     Material Contract                                   HTML    153K 
 3: EX-31.1     Certification -- §302 - SOA'02                      HTML     25K 
 4: EX-31.2     Certification -- §302 - SOA'02                      HTML     25K 
 5: EX-32.1     Certification -- §906 - SOA'02                      HTML     21K 
 6: EX-32.2     Certification -- §906 - SOA'02                      HTML     21K 
12: R1          Cover                                               HTML     74K 
13: R2          Condensed Consolidated Balance Sheets               HTML    143K 
14: R3          Condensed Consolidated Balance Sheets               HTML     37K 
                (Parenthetical)                                                  
15: R4          Condensed Consolidated Statements of Operations     HTML    163K 
16: R5          Condensed Consolidated Statements of Comprehensive  HTML     47K 
                Income (Loss)                                                    
17: R6          Condensed Consolidated Statements of Stockholders?  HTML    109K 
                Equity                                                           
18: R7          Condensed Consolidated Statements of Cash Flows     HTML    147K 
19: R8          Summary of Significant Accounting Policies          HTML     30K 
20: R9          Acquisitions                                        HTML     55K 
21: R10         Revenue Recognition                                 HTML     99K 
22: R11         Discontinued Operations                             HTML     23K 
23: R12         Goodwill and Intangible Assets                      HTML     68K 
24: R13         Inventoried Costs                                   HTML     29K 
25: R14         Net Income (Loss) per Common Share                  HTML     24K 
26: R15         Leases                                              HTML    166K 
27: R16         Income Taxes                                        HTML     43K 
28: R17         Debt                                                HTML     52K 
29: R18         Segment Information                                 HTML     69K 
30: R19         Redeemable Noncontrolling Interest                  HTML     26K 
31: R20         Significant Customers                               HTML     23K 
32: R21         Commitments and Contingencies                       HTML     28K 
33: R22         Summary of Significant Accounting Policies          HTML     41K 
                (Policies)                                                       
34: R23         Acquisitions (Tables)                               HTML     46K 
35: R24         Revenue Recognition (Tables)                        HTML     80K 
36: R25         Goodwill and Intangible Assets (Tables)             HTML    105K 
37: R26         Inventoried Costs (Tables)                          HTML     30K 
38: R27         Leases (Tables)                                     HTML    108K 
39: R28         Income Taxes (Tables)                               HTML     39K 
40: R29         Debt (Tables)                                       HTML     47K 
41: R30         Segment Information (Tables)                        HTML     63K 
42: R31         Summary of Significant Accounting Policies          HTML     25K 
                (Details)                                                        
43: R32         Acquisitions - Narrative (Details)                  HTML     73K 
44: R33         Acquisitions - Assets Acquired and Liabilities      HTML     51K 
                Assumed (Details)                                                
45: R34         Acquisitions - Consideration Paid (Details)         HTML     31K 
46: R35         Revenue Recognition - Remaining Performance         HTML     32K 
                Obligations (Details)                                            
47: R36         Revenue Recognition - Contract Assets and           HTML     32K 
                Liabilities (Details)                                            
48: R37         Revenue Recognition - Narrative (Details)           HTML     43K 
49: R38         Revenue Recognition - Disaggregation of Revenue     HTML     52K 
                (Details)                                                        
50: R39         Discontinued Operations (Details)                   HTML     29K 
51: R40         Goodwill and Intangible Assets - Goodwill           HTML     34K 
                (Details)                                                        
52: R41         Goodwill and Intangible Assets - Purchased          HTML     56K 
                Intangible Assets (Details)                                      
53: R42         Inventoried Costs (Details)                         HTML     29K 
54: R43         Net Income (Loss) per Common Share (Details)        HTML     24K 
55: R44         Leases - Lease Expense (Details)                    HTML     37K 
56: R45         Leases - Supplemental Balance Sheet (Details)       HTML     41K 
57: R46         Leases - Cash Paid (Details)                        HTML     27K 
58: R47         Leases - Weighted Average (Details)                 HTML     39K 
59: R48         Leases - Maturities of Operating and Financing      HTML     59K 
                Lease Liabilities (Details)                                      
60: R49         Income Taxes - Income Tax Provision Reconciliation  HTML     34K 
                (Details)                                                        
61: R50         Income Taxes - Narrative (Details)                  HTML     29K 
62: R51         Debt - New Credit Facility (Details)                HTML    115K 
63: R52         Debt - Long-Term Debt and the Current Period        HTML     42K 
                Interest Rates (Details)                                         
64: R53         Debt - Future Long-Term Debt Principal Payments     HTML     42K 
                (Details)                                                        
65: R54         Debt - Issuance of 6.5% Senior Secured Notes due    HTML     31K 
                2025 (Details)                                                   
66: R55         Debt - Other Indebtedness (Details)                 HTML     41K 
67: R56         Debt - Fair Value of Long-term Debt (Details)       HTML     28K 
68: R57         Segment Information - Narrative (Details)           HTML     26K 
69: R58         Segment Information - Schedule of Segment           HTML     57K 
                Revenues, Depreciation and Amortization, and                     
                Operating (Loss) (Details)                                       
70: R59         Redeemable Noncontrolling Interest (Details)        HTML     42K 
71: R60         Significant Customers (Details)                     HTML     37K 
74: XML         IDEA XML File -- Filing Summary                      XML    131K 
72: XML         XBRL Instance -- ktos-20220626_htm                   XML   2.07M 
73: EXCEL       IDEA Workbook of Financial Reports                  XLSX    128K 
 8: EX-101.CAL  XBRL Calculations -- ktos-20220626_cal               XML    261K 
 9: EX-101.DEF  XBRL Definitions -- ktos-20220626_def                XML    510K 
10: EX-101.LAB  XBRL Labels -- ktos-20220626_lab                     XML   1.46M 
11: EX-101.PRE  XBRL Presentations -- ktos-20220626_pre              XML    876K 
 7: EX-101.SCH  XBRL Schema -- ktos-20220626                         XSD    133K 
75: JSON        XBRL Instance as JSON Data -- MetaLinks              385±   583K 
76: ZIP         XBRL Zipped Folder -- 0001069258-22-000054-xbrl      Zip    407K

‘EX-101.DEF’   —   XBRL Definitions — ktos-20220626_def

This Exhibit is an XBRL XML File.

                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with Wdesk from Workiva -->
<!-- Copyright 2022 Workiva -->
<!-- r:f42bc7ed-7f65-49a8-84df-2b4c8138c469,g:d9920d86-5239-4c03-8681-09db6779bc69 -->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
<link:roleRef roleURI="http://www.kratosdefense.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="ktos-20220626.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended" id="ia0f8504bc1e24d63aacc79e1abec5fcb_CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e0d0cde3-d848-4709-aade-e72faeaa2ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e0d0cde3-d848-4709-aade-e72faeaa2ce8" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_4ac79267-f848-4f98-8cff-17a94fcdfcf8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_4ac79267-f848-4f98-8cff-17a94fcdfcf8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_fbb17afd-1434-4500-a45e-182349e6a17b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GrossProfit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_GrossProfit_fbb17afd-1434-4500-a45e-182349e6a17b" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_da5d9d8f-7bb6-4b88-8cb1-bd5cd09dfff6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_da5d9d8f-7bb6-4b88-8cb1-bd5cd09dfff6" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_8be9e314-39ed-4d61-ad53-63ec91c2cae2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_8be9e314-39ed-4d61-ad53-63ec91c2cae2" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_8518ffa0-c2d5-4082-80b1-33e642ce7010" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_8518ffa0-c2d5-4082-80b1-33e642ce7010" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ImpairmentChargesAndAdjustmentsToUnusedOfficeSpaceLiability_01427d85-55c1-4735-9826-c5865271e75a" xlink:href="ktos-20220626.xsd#ktos_ImpairmentChargesAndAdjustmentsToUnusedOfficeSpaceLiability"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_ktos_ImpairmentChargesAndAdjustmentsToUnusedOfficeSpaceLiability_01427d85-55c1-4735-9826-c5865271e75a" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_e8c02844-2578-43af-bee5-ae9478314485" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_OperatingIncomeLoss_e8c02844-2578-43af-bee5-ae9478314485" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_4d387c5d-4594-4a8d-8f9d-285ca3d6ec62" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_4d387c5d-4594-4a8d-8f9d-285ca3d6ec62" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_895c0022-230f-47bf-8a65-aa77c12fa309" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_895c0022-230f-47bf-8a65-aa77c12fa309" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_5abb67af-d63c-42d7-9959-d38cf157f790" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_5abb67af-d63c-42d7-9959-d38cf157f790" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_96b15fdd-98cc-4749-a559-f3885a7082ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_aea455f6-1eea-44e9-823a-8f5aeef97f06" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_96b15fdd-98cc-4749-a559-f3885a7082ad" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_44633706-9797-4c41-a386-c1f7f4513b0c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_44633706-9797-4c41-a386-c1f7f4513b0c" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_fa9c34fb-3184-4617-8a54-525836533946" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_fa9c34fb-3184-4617-8a54-525836533946" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_7f177c54-35f4-4951-82c7-4769505d0328" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_7f177c54-35f4-4951-82c7-4769505d0328" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_38d59754-1319-4621-9df9-6d7191c836c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_38d59754-1319-4621-9df9-6d7191c836c3" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_1bf362a2-a735-4358-8c85-c12223c20e01" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_1bf362a2-a735-4358-8c85-c12223c20e01" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_8db69eda-b214-447d-8533-aaa0668af469" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_8db69eda-b214-447d-8533-aaa0668af469" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_735f4aba-8cc5-4a00-bc8a-103bccf626b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_ProfitLoss_735f4aba-8cc5-4a00-bc8a-103bccf626b8" xlink:type="arc" order="15"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_546f2e60-5f95-426b-96f7-46fda8f5a0bd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_546f2e60-5f95-426b-96f7-46fda8f5a0bd" xlink:type="arc" order="16"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_b3f47fc2-49a8-4fe3-abfb-f34332580681" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_NetIncomeLoss_b3f47fc2-49a8-4fe3-abfb-f34332580681" xlink:type="arc" order="17"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_387603e6-6c61-4cac-afa6-2093eef857a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_387603e6-6c61-4cac-afa6-2093eef857a2" xlink:type="arc" order="18"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_5b2e600d-2641-431f-8d66-3fcf361cb0c8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_387603e6-6c61-4cac-afa6-2093eef857a2" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_5b2e600d-2641-431f-8d66-3fcf361cb0c8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerBasicShare_1e967ecf-9b8f-423b-bf6f-67f7fe187ebe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerBasicShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_387603e6-6c61-4cac-afa6-2093eef857a2" xlink:to="loc_us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerBasicShare_1e967ecf-9b8f-423b-bf6f-67f7fe187ebe" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_63320d97-1848-4f63-ad41-8acd789ce367" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasic"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_387603e6-6c61-4cac-afa6-2093eef857a2" xlink:to="loc_us-gaap_EarningsPerShareBasic_63320d97-1848-4f63-ad41-8acd789ce367" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_b83c88ab-e5a6-4399-8224-12a221a8aa57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_b83c88ab-e5a6-4399-8224-12a221a8aa57" xlink:type="arc" order="19"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_68c1eacb-e1b1-4f9b-830c-65961da37437" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_b83c88ab-e5a6-4399-8224-12a221a8aa57" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_68c1eacb-e1b1-4f9b-830c-65961da37437" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare_69eebdf4-9242-456f-92d1-e0090525a370" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_b83c88ab-e5a6-4399-8224-12a221a8aa57" xlink:to="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare_69eebdf4-9242-456f-92d1-e0090525a370" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_5f32b823-980c-4d54-8e46-68ed1a20d42f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareDiluted"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_b83c88ab-e5a6-4399-8224-12a221a8aa57" xlink:to="loc_us-gaap_EarningsPerShareDiluted_5f32b823-980c-4d54-8e46-68ed1a20d42f" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareReconciliationAbstract_2a3c5bb6-8038-4f91-a260-50eaa4884dff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareReconciliationAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_EarningsPerShareReconciliationAbstract_2a3c5bb6-8038-4f91-a260-50eaa4884dff" xlink:type="arc" order="20"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_3c748715-dcac-4973-a9fe-6d64dc1c00bb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_2a3c5bb6-8038-4f91-a260-50eaa4884dff" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_3c748715-dcac-4973-a9fe-6d64dc1c00bb" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_3d7f869b-cbec-4f9e-ae3f-be2c40ad893a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_2a3c5bb6-8038-4f91-a260-50eaa4884dff" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_3d7f869b-cbec-4f9e-ae3f-be2c40ad893a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_23c3bd36-7bab-4c10-ba95-5ef0260f8c7d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_8735aaf2-0d81-4107-a494-e365b37d2d16" xlink:to="loc_us-gaap_StatementTable_23c3bd36-7bab-4c10-ba95-5ef0260f8c7d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_e3cd8c1f-77b1-4934-aa71-3a73406279bf" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_23c3bd36-7bab-4c10-ba95-5ef0260f8c7d" xlink:to="loc_srt_ProductOrServiceAxis_e3cd8c1f-77b1-4934-aa71-3a73406279bf" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_e3cd8c1f-77b1-4934-aa71-3a73406279bf_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_e3cd8c1f-77b1-4934-aa71-3a73406279bf" xlink:to="loc_srt_ProductsAndServicesDomain_e3cd8c1f-77b1-4934-aa71-3a73406279bf_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_29be09fe-9510-4b80-8af7-6eee56327a94" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_e3cd8c1f-77b1-4934-aa71-3a73406279bf" xlink:to="loc_srt_ProductsAndServicesDomain_29be09fe-9510-4b80-8af7-6eee56327a94" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_490924fc-2ac6-43c0-b09c-953c6d549407" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ServiceMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_29be09fe-9510-4b80-8af7-6eee56327a94" xlink:to="loc_us-gaap_ServiceMember_490924fc-2ac6-43c0-b09c-953c6d549407" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_26fb85dc-9304-4e13-87e0-1b9b30a99c37" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_29be09fe-9510-4b80-8af7-6eee56327a94" xlink:to="loc_us-gaap_ProductMember_26fb85dc-9304-4e13-87e0-1b9b30a99c37" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="ktos-20220626.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended" id="i22f965327bdb4941bb88a72d38850f9f_CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_2d58e752-2999-41ef-a55f-6fb0658a2e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInMinorityInterestRollForward_39ed2b44-9132-4df6-97f9-591401c07bfc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MovementInMinorityInterestRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2d58e752-2999-41ef-a55f-6fb0658a2e3a" xlink:to="loc_us-gaap_MovementInMinorityInterestRollForward_39ed2b44-9132-4df6-97f9-591401c07bfc" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_3e14a2f3-fb1c-4da0-a917-aec3af1ad76a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_39ed2b44-9132-4df6-97f9-591401c07bfc" xlink:to="loc_us-gaap_MinorityInterest_3e14a2f3-fb1c-4da0-a917-aec3af1ad76a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_c1409575-d33c-4515-b0d9-f1ef727efc9d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_39ed2b44-9132-4df6-97f9-591401c07bfc" xlink:to="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_c1409575-d33c-4515-b0d9-f1ef727efc9d" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestPeriodIncreaseDecrease_e448ba7d-75ae-41fe-b40c-cafc0c8fbbe2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestPeriodIncreaseDecrease"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_39ed2b44-9132-4df6-97f9-591401c07bfc" xlink:to="loc_us-gaap_MinorityInterestPeriodIncreaseDecrease_e448ba7d-75ae-41fe-b40c-cafc0c8fbbe2" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_f2d8f2a2-26d7-4001-9994-e8faa722bda6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterest"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2d58e752-2999-41ef-a55f-6fb0658a2e3a" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_23f7980d-7756-4726-9f81-ed15a5bbc458" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_23f7980d-7756-4726-9f81-ed15a5bbc458" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_0813e1b9-a573-45cc-91a8-414dc2304919" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_0813e1b9-a573-45cc-91a8-414dc2304919" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_72e901f0-91d7-4a5f-914c-93c02cacc910" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_72e901f0-91d7-4a5f-914c-93c02cacc910" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_609c1082-2655-45bc-87c9-1a9aee865f7a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_609c1082-2655-45bc-87c9-1a9aee865f7a" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_108a44e2-b63b-4f42-b32f-1b38e8540fd4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_108a44e2-b63b-4f42-b32f-1b38e8540fd4" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_7c832f0d-c660-4883-8344-485704ae30be" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_7c832f0d-c660-4883-8344-485704ae30be" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_ce9db9c5-3786-48e1-a051-9276c6c25b8d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_ce9db9c5-3786-48e1-a051-9276c6c25b8d" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_87d1a361-f362-47f0-86f5-c717475fda23" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_87d1a361-f362-47f0-86f5-c717475fda23" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_2dd92e58-98ac-40ce-b2cb-e1a382e2d55e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_2dd92e58-98ac-40ce-b2cb-e1a382e2d55e" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_de3fa5a0-ec03-4351-9de4-9f5efebcdad3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_NetIncomeLoss_de3fa5a0-ec03-4351-9de4-9f5efebcdad3" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_a2863856-7125-4e67-a184-e96b6e33aa52" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_a2863856-7125-4e67-a184-e96b6e33aa52" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_IncreaseFromSubsidiaryEquityIssuanceOfSharesInNoncontrollingInterest_2471bc4e-3dae-4d9d-908d-51dfc26c88bf" xlink:href="ktos-20220626.xsd#ktos_IncreaseFromSubsidiaryEquityIssuanceOfSharesInNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5b613699-7165-4d31-95ff-2ebe39a8bbae" xlink:to="loc_ktos_IncreaseFromSubsidiaryEquityIssuanceOfSharesInNoncontrollingInterest_2471bc4e-3dae-4d9d-908d-51dfc26c88bf" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestPeriodIncreaseDecrease_4645d6a0-0521-497f-ba89-86c217bb1475" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestPeriodIncreaseDecrease"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_871dde5f-3090-4e19-9166-e28ebcee280c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_a4602dfd-daaa-4763-8c55-8789c9ba4000" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_fd9df559-a2b9-4a25-8a8e-7cba274eb4de" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2d58e752-2999-41ef-a55f-6fb0658a2e3a" xlink:to="loc_us-gaap_StatementTable_fd9df559-a2b9-4a25-8a8e-7cba274eb4de" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_56a34c93-11c6-45c0-82ca-bc03234b6e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_fd9df559-a2b9-4a25-8a8e-7cba274eb4de" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_56a34c93-11c6-45c0-82ca-bc03234b6e9c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_56a34c93-11c6-45c0-82ca-bc03234b6e9c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_56a34c93-11c6-45c0-82ca-bc03234b6e9c" xlink:to="loc_us-gaap_EquityComponentDomain_56a34c93-11c6-45c0-82ca-bc03234b6e9c_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_56a34c93-11c6-45c0-82ca-bc03234b6e9c" xlink:to="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_d093f8a4-3792-4034-84eb-e6179bd556dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:to="loc_us-gaap_NoncontrollingInterestMember_d093f8a4-3792-4034-84eb-e6179bd556dc" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_b4147111-db93-4b19-856c-3e3bb8e16666" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:to="loc_us-gaap_CommonStockMember_b4147111-db93-4b19-856c-3e3bb8e16666" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_e9866615-d394-4c77-add6-7fa4051d0af0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_e9866615-d394-4c77-add6-7fa4051d0af0" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d4a72124-b534-4360-be49-9e845b8fb225" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d4a72124-b534-4360-be49-9e845b8fb225" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_2b190126-8eaf-43f9-80c2-7df51220b30b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a9d1d573-c9c5-498d-a7a3-0c73b9737351" xlink:to="loc_us-gaap_RetainedEarningsMember_2b190126-8eaf-43f9-80c2-7df51220b30b" xlink:type="arc" order="4"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#SummaryofSignificantAccountingPoliciesDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="extended" id="i98d4f430a6ad4ca38c031ae656369300_SummaryofSignificantAccountingPoliciesDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_a429140e-7632-4b0f-a591-6b5177d3b860" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_59c21a3d-010c-4e05-b89b-db646eb2cb64" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_a429140e-7632-4b0f-a591-6b5177d3b860" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_59c21a3d-010c-4e05-b89b-db646eb2cb64" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_cf0b1607-a2de-4d76-bb3d-3ad8dfbfb56d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_a429140e-7632-4b0f-a591-6b5177d3b860" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_cf0b1607-a2de-4d76-bb3d-3ad8dfbfb56d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9e6ba824-5d1f-448e-b150-cbac3573fa79" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_a429140e-7632-4b0f-a591-6b5177d3b860" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9e6ba824-5d1f-448e-b150-cbac3573fa79" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_b345928a-91c3-450f-8a68-617d10414f82" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9e6ba824-5d1f-448e-b150-cbac3573fa79" xlink:to="loc_srt_OwnershipAxis_b345928a-91c3-450f-8a68-617d10414f82" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_b345928a-91c3-450f-8a68-617d10414f82_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_b345928a-91c3-450f-8a68-617d10414f82" xlink:to="loc_srt_OwnershipDomain_b345928a-91c3-450f-8a68-617d10414f82_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_3898e3e3-46ff-4a04-8d21-ef6e8764e243" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_b345928a-91c3-450f-8a68-617d10414f82" xlink:to="loc_srt_OwnershipDomain_3898e3e3-46ff-4a04-8d21-ef6e8764e243" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KTTCORELLCMember_06a0d4aa-2d63-468f-9826-a5071972e019" xlink:href="ktos-20220626.xsd#ktos_KTTCORELLCMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_3898e3e3-46ff-4a04-8d21-ef6e8764e243" xlink:to="loc_ktos_KTTCORELLCMember_06a0d4aa-2d63-468f-9826-a5071972e019" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/AcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#AcquisitionsNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/AcquisitionsNarrativeDetails" xlink:type="extended" id="i3f59da799d2944e8adbfd2eca222726a_AcquisitionsNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_af05bfb4-842c-4a16-900e-bfa91855e798" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_af05bfb4-842c-4a16-900e-bfa91855e798" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_PaymentsToAcquireBusinessGrossSubjectToAdjustments_fa9cb4e3-060e-41b9-8195-af566b8e1867" xlink:href="ktos-20220626.xsd#ktos_PaymentsToAcquireBusinessGrossSubjectToAdjustments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_ktos_PaymentsToAcquireBusinessGrossSubjectToAdjustments_fa9cb4e3-060e-41b9-8195-af566b8e1867" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_7fc0f774-0656-4a1d-8de8-706821afec49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_7fc0f774-0656-4a1d-8de8-706821afec49" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_e0dcc063-0f1a-4c8f-b951-d26c6529dc89" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_e0dcc063-0f1a-4c8f-b951-d26c6529dc89" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_b9ab20e5-0ce0-47a4-8028-9e437b3f7634" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_b9ab20e5-0ce0-47a4-8028-9e437b3f7634" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilities_e0ff846b-2423-4cc4-8df9-213429e2ce06" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxLiabilities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_DeferredTaxLiabilities_e0ff846b-2423-4cc4-8df9-213429e2ce06" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_a720c3fa-18b8-4d08-8a33-bcb4d1e74000" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_a720c3fa-18b8-4d08-8a33-bcb4d1e74000" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_5ae03a36-a1f4-42e1-968b-7407b610c131" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_5ae03a36-a1f4-42e1-968b-7407b610c131" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_679988d6-27c7-45dd-9f1e-3e953172042c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_679988d6-27c7-45dd-9f1e-3e953172042c" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_54f07058-9785-4131-8f1b-1849dc1d7e17" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_54f07058-9785-4131-8f1b-1849dc1d7e17" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_f4ed33e2-a312-4d5d-954b-d9a67a84840a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_f4ed33e2-a312-4d5d-954b-d9a67a84840a" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3e349020-4f5b-4b12-8500-d4bbf553d08d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_57549e47-9742-4e0e-84d4-34bb0757cf7a" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3e349020-4f5b-4b12-8500-d4bbf553d08d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2d428d7f-fe07-4043-a220-834d823cc89e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3e349020-4f5b-4b12-8500-d4bbf553d08d" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2d428d7f-fe07-4043-a220-834d823cc89e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2d428d7f-fe07-4043-a220-834d823cc89e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2d428d7f-fe07-4043-a220-834d823cc89e" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2d428d7f-fe07-4043-a220-834d823cc89e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31c45b3d-e7d2-4a03-895a-4fb5adf2d40b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2d428d7f-fe07-4043-a220-834d823cc89e" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31c45b3d-e7d2-4a03-895a-4fb5adf2d40b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_CTTIncMember_5b7ef7fc-feb7-40b0-b004-0d78d6a9c130" xlink:href="ktos-20220626.xsd#ktos_CTTIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31c45b3d-e7d2-4a03-895a-4fb5adf2d40b" xlink:to="loc_ktos_CTTIncMember_5b7ef7fc-feb7-40b0-b004-0d78d6a9c130" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_d4f1d100-fdc8-4d4b-8ceb-aa03e3dc168c" xlink:href="ktos-20220626.xsd#ktos_CosmicAdvancedEngineeringSolutionsIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31c45b3d-e7d2-4a03-895a-4fb5adf2d40b" xlink:to="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_d4f1d100-fdc8-4d4b-8ceb-aa03e3dc168c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_SouthernResearchEngineeringDivisionMember_86358101-6633-4c6d-b171-7848c2349096" xlink:href="ktos-20220626.xsd#ktos_SouthernResearchEngineeringDivisionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31c45b3d-e7d2-4a03-895a-4fb5adf2d40b" xlink:to="loc_ktos_SouthernResearchEngineeringDivisionMember_86358101-6633-4c6d-b171-7848c2349096" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_47488ce4-6e2c-4c59-85ef-173671704b08" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3e349020-4f5b-4b12-8500-d4bbf553d08d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_47488ce4-6e2c-4c59-85ef-173671704b08" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_47488ce4-6e2c-4c59-85ef-173671704b08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_47488ce4-6e2c-4c59-85ef-173671704b08" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_47488ce4-6e2c-4c59-85ef-173671704b08_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_47488ce4-6e2c-4c59-85ef-173671704b08" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_d7ca2b4f-e389-47d6-8232-1d4f7bf0c059" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TradeNamesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:to="loc_us-gaap_TradeNamesMember_d7ca2b4f-e389-47d6-8232-1d4f7bf0c059" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ContractsAndBacklogMember_d50368cf-fee1-46c1-abf8-3ae70f876316" xlink:href="ktos-20220626.xsd#ktos_ContractsAndBacklogMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:to="loc_ktos_ContractsAndBacklogMember_d50368cf-fee1-46c1-abf8-3ae70f876316" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_bb2a98cd-e6aa-41cf-a854-435cb1bfa0cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:to="loc_us-gaap_CustomerRelationshipsMember_bb2a98cd-e6aa-41cf-a854-435cb1bfa0cb" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_6c6c4be3-53c0-4190-ae42-686bb9ae640c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_6c6c4be3-53c0-4190-ae42-686bb9ae640c" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_2351760c-24f6-4966-880c-9f8fb96c672f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InProcessResearchAndDevelopmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_24c7a48f-6b3c-41e5-bf97-9d1bfbaba1cf" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_2351760c-24f6-4966-880c-9f8fb96c672f" xlink:type="arc" order="4"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/AcquisitionsAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#AcquisitionsAssetsAcquiredandLiabilitiesAssumedDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/AcquisitionsAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended" id="i55654162028c4f4bb49ca7e6b075ce5c_AcquisitionsAssetsAcquiredandLiabilitiesAssumedDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_6a295077-10d7-4638-a68e-dad9438b5650" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_6a295077-10d7-4638-a68e-dad9438b5650" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentAssetsUnbilledReceivables_a3802982-a3db-4c93-b196-9fe6a2b2cb11" xlink:href="ktos-20220626.xsd#ktos_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentAssetsUnbilledReceivables"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_ktos_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentAssetsUnbilledReceivables_a3802982-a3db-4c93-b196-9fe6a2b2cb11" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_32e6e856-ca98-4f51-8442-66a6e157f091" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_32e6e856-ca98-4f51-8442-66a6e157f091" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_896fabcb-6d9b-4383-806b-124a84be6230" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_896fabcb-6d9b-4383-806b-124a84be6230" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_ec5fe570-2438-47cb-9232-720bf3600795" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_ec5fe570-2438-47cb-9232-720bf3600795" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_5089d5ae-66ee-490f-96c7-edabc1e17adf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_5089d5ae-66ee-490f-96c7-edabc1e17adf" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ce21c9f0-cf0b-4f34-ad93-adbe265adb5b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ce21c9f0-cf0b-4f34-ad93-adbe265adb5b" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_b0cc53e4-b3d1-4083-b3a3-41127e0cb87b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_b0cc53e4-b3d1-4083-b3a3-41127e0cb87b" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_83942b90-5916-40d2-8707-18c58f4fa43c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_83942b90-5916-40d2-8707-18c58f4fa43c" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_f9a571f3-ecef-4c92-bd36-ab53cc255cb5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_Goodwill_f9a571f3-ecef-4c92-bd36-ab53cc255cb5" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_9cf782f6-592f-44f3-98a6-7c3365b1cb61" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_9cf782f6-592f-44f3-98a6-7c3365b1cb61" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_c6f7e1cd-b1ae-4c7c-8cdf-769739c3d83c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_70fc7dc6-977b-40e3-8c1e-aba87a88125b" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_c6f7e1cd-b1ae-4c7c-8cdf-769739c3d83c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_c6f7e1cd-b1ae-4c7c-8cdf-769739c3d83c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f18a26b3-b506-49c9-9e96-b749a90cdb58" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b4b0c3ba-d2d3-43a6-91e0-3ce8c6668157" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f18a26b3-b506-49c9-9e96-b749a90cdb58" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_4b6700be-c253-49a6-a724-5f4eebc40483" xlink:href="ktos-20220626.xsd#ktos_CosmicAdvancedEngineeringSolutionsIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f18a26b3-b506-49c9-9e96-b749a90cdb58" xlink:to="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_4b6700be-c253-49a6-a724-5f4eebc40483" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/AcquisitionsConsiderationPaidDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#AcquisitionsConsiderationPaidDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/AcquisitionsConsiderationPaidDetails" xlink:type="extended" id="i83439828b54a4119b48476824d49f5e2_AcquisitionsConsiderationPaidDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_c73f62fb-730f-4994-9249-f2d26b8c887a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_c73f62fb-730f-4994-9249-f2d26b8c887a" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_afcfdffa-ade9-48ec-8308-b3fcf1c77c09" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAcquiredFromAcquisition"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_afcfdffa-ade9-48ec-8308-b3fcf1c77c09" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_a91838f7-978c-4394-a87c-59f7867c29e7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_a91838f7-978c-4394-a87c-59f7867c29e7" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_200f3424-521b-497f-9670-682ea4c2a08e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_200f3424-521b-497f-9670-682ea4c2a08e" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_133fcc7b-2b09-40b5-953b-8ba00565e231" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_168166ac-b6fe-4596-a348-81be2b99fed4" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_133fcc7b-2b09-40b5-953b-8ba00565e231" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_133fcc7b-2b09-40b5-953b-8ba00565e231" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31df6f30-8c90-481c-8ba6-205b05dedd41" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d7c8d8e6-6d8f-4545-88ec-aecf0becd99d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31df6f30-8c90-481c-8ba6-205b05dedd41" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_7e3682c1-e9b5-4775-889d-50ecd02be6ed" xlink:href="ktos-20220626.xsd#ktos_CosmicAdvancedEngineeringSolutionsIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_31df6f30-8c90-481c-8ba6-205b05dedd41" xlink:to="loc_ktos_CosmicAdvancedEngineeringSolutionsIncMember_7e3682c1-e9b5-4775-889d-50ecd02be6ed" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/RevenueRecognitionRemainingPerformanceObligationsDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#RevenueRecognitionRemainingPerformanceObligationsDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/RevenueRecognitionRemainingPerformanceObligationsDetails" xlink:type="extended" id="ibc40fa5ca0ca42ad9f9eef82d2812065_RevenueRecognitionRemainingPerformanceObligationsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_4d612a3d-992b-4360-ae11-8267f7086f86" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_4d612a3d-992b-4360-ae11-8267f7086f86" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_cc311cba-acc6-48d7-a412-b0f6e8912fa5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_cc311cba-acc6-48d7-a412-b0f6e8912fa5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_fa25b3bc-89b1-49bd-9a7a-52afcfed5d12" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_fa25b3bc-89b1-49bd-9a7a-52afcfed5d12" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_0b899731-c59e-425e-82bd-ac4f72098b8f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_fa25b3bc-89b1-49bd-9a7a-52afcfed5d12" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_0b899731-c59e-425e-82bd-ac4f72098b8f" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/RevenueRecognitionRemainingPerformanceObligationsDetails_1" xlink:type="simple" xlink:href="ktos-20220626.xsd#RevenueRecognitionRemainingPerformanceObligationsDetails_1"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/RevenueRecognitionRemainingPerformanceObligationsDetails_1" xlink:type="extended" id="i534b842eef8e4ffcb52acb09cde6311e_RevenueRecognitionRemainingPerformanceObligationsDetails_1">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_4d612a3d-992b-4360-ae11-8267f7086f86" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_4d612a3d-992b-4360-ae11-8267f7086f86" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_cc311cba-acc6-48d7-a412-b0f6e8912fa5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_cc311cba-acc6-48d7-a412-b0f6e8912fa5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_fa25b3bc-89b1-49bd-9a7a-52afcfed5d12" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_08f5f339-87d8-4cc9-875c-091373f7016b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_fa25b3bc-89b1-49bd-9a7a-52afcfed5d12" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/RevenueRecognitionNarrativeDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#RevenueRecognitionNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/RevenueRecognitionNarrativeDetails" xlink:type="extended" id="if355f9116d444d1c9839b3e5bbe96a9e_RevenueRecognitionNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ContractWithCustomerAssetIncreaseDecrease_283d1a9b-4469-4689-bedb-4c91411c1d88" xlink:href="ktos-20220626.xsd#ktos_ContractWithCustomerAssetIncreaseDecrease"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_ktos_ContractWithCustomerAssetIncreaseDecrease_283d1a9b-4469-4689-bedb-4c91411c1d88" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ContractWithCustomerLiabilityIncreaseDecrease_c712ed52-ff8a-408e-bbb1-f15ad61899c9" xlink:href="ktos-20220626.xsd#ktos_ContractWithCustomerLiabilityIncreaseDecrease"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_ktos_ContractWithCustomerLiabilityIncreaseDecrease_c712ed52-ff8a-408e-bbb1-f15ad61899c9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_d5572fcb-6859-4164-8ed3-d7c5d35dadef" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_d5572fcb-6859-4164-8ed3-d7c5d35dadef" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNet_c133dc3e-e4dc-4c2b-8cba-db47d3531228" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerAssetNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_us-gaap_ContractWithCustomerAssetNet_c133dc3e-e4dc-4c2b-8cba-db47d3531228" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetReclassifiedToReceivable_cb7af2bb-d20c-433c-b8d8-6d6c6ba03a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerAssetReclassifiedToReceivable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_us-gaap_ContractWithCustomerAssetReclassifiedToReceivable_cb7af2bb-d20c-433c-b8d8-6d6c6ba03a7f" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ContractWithCustomerAssetSubjectToNegotiationAndSettlementWithTheCustomer_6289b00e-8a85-4fbc-86f8-a9223b5b4a95" xlink:href="ktos-20220626.xsd#ktos_ContractWithCustomerAssetSubjectToNegotiationAndSettlementWithTheCustomer"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_ktos_ContractWithCustomerAssetSubjectToNegotiationAndSettlementWithTheCustomer_6289b00e-8a85-4fbc-86f8-a9223b5b4a95" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_2333c35e-7741-40ac-90f8-529b3d5bede0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_us-gaap_LitigationSettlementExpense_2333c35e-7741-40ac-90f8-529b3d5bede0" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRecognitionMilestoneMethodTable_8763d8e3-b060-465f-b2ec-63a1912f4de2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRecognitionMilestoneMethodTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems_da765eaa-16b0-443f-adfe-fe95878f8e1f" xlink:to="loc_us-gaap_RevenueRecognitionMilestoneMethodTable_8763d8e3-b060-465f-b2ec-63a1912f4de2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_27e84b15-0f70-4db9-9eb2-bdc508e06fc1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRecognitionMilestoneMethodTable_8763d8e3-b060-465f-b2ec-63a1912f4de2" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_27e84b15-0f70-4db9-9eb2-bdc508e06fc1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_27e84b15-0f70-4db9-9eb2-bdc508e06fc1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_27e84b15-0f70-4db9-9eb2-bdc508e06fc1" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_27e84b15-0f70-4db9-9eb2-bdc508e06fc1_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_068b4b20-c9fc-4505-81ad-cb163ed176f2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_27e84b15-0f70-4db9-9eb2-bdc508e06fc1" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_068b4b20-c9fc-4505-81ad-cb163ed176f2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledRevenuesMember_a58f78e7-725f-47f7-8c46-2b24511a9b73" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnbilledRevenuesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivablesBillingStatusDomain_068b4b20-c9fc-4505-81ad-cb163ed176f2" xlink:to="loc_us-gaap_UnbilledRevenuesMember_a58f78e7-725f-47f7-8c46-2b24511a9b73" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_53fbb723-2b42-43de-a4c8-5e4f88535bd9" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRecognitionMilestoneMethodTable_8763d8e3-b060-465f-b2ec-63a1912f4de2" xlink:to="loc_srt_MajorCustomersAxis_53fbb723-2b42-43de-a4c8-5e4f88535bd9" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_53fbb723-2b42-43de-a4c8-5e4f88535bd9_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_53fbb723-2b42-43de-a4c8-5e4f88535bd9" xlink:to="loc_srt_NameOfMajorCustomerDomain_53fbb723-2b42-43de-a4c8-5e4f88535bd9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_99028aff-2247-424a-b606-baa3652664a9" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_53fbb723-2b42-43de-a4c8-5e4f88535bd9" xlink:to="loc_srt_NameOfMajorCustomerDomain_99028aff-2247-424a-b606-baa3652664a9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_TforCMember_94528239-8eae-4f78-9ed8-2259845373a7" xlink:href="ktos-20220626.xsd#ktos_TforCMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_99028aff-2247-424a-b606-baa3652664a9" xlink:to="loc_ktos_TforCMember_94528239-8eae-4f78-9ed8-2259845373a7" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRecognitionMilestoneMethodTable_8763d8e3-b060-465f-b2ec-63a1912f4de2" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b" xlink:to="loc_us-gaap_SegmentDomain_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_fbf7f3da-1aa9-4618-8a43-cf7c14e08354" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_04cc31cc-702a-4f2d-ab59-fdfc872f0e1b" xlink:to="loc_us-gaap_SegmentDomain_fbf7f3da-1aa9-4618-8a43-cf7c14e08354" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosUnmannedSystemsMember_64b70286-02e5-4b50-84cb-3ab94d9779ae" xlink:href="ktos-20220626.xsd#ktos_KratosUnmannedSystemsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fbf7f3da-1aa9-4618-8a43-cf7c14e08354" xlink:to="loc_ktos_KratosUnmannedSystemsMember_64b70286-02e5-4b50-84cb-3ab94d9779ae" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#RevenueRecognitionDisaggregationofRevenueDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="extended" id="i66fa2504313d40909e4e9e7b9ab5e3ba_RevenueRecognitionDisaggregationofRevenueDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_1396be6f-b484-4294-b77b-a8bf018a45f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_83a180de-0f2c-4454-9f18-d0b1497c0ec0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_1396be6f-b484-4294-b77b-a8bf018a45f6" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_83a180de-0f2c-4454-9f18-d0b1497c0ec0" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_e6884934-8517-4878-9c9c-43178656b73a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_1396be6f-b484-4294-b77b-a8bf018a45f6" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_e6884934-8517-4878-9c9c-43178656b73a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_21d361a5-4718-4817-a6d2-000701db3c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_e6884934-8517-4878-9c9c-43178656b73a" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_21d361a5-4718-4817-a6d2-000701db3c7e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_21d361a5-4718-4817-a6d2-000701db3c7e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_21d361a5-4718-4817-a6d2-000701db3c7e" xlink:to="loc_us-gaap_SegmentDomain_21d361a5-4718-4817-a6d2-000701db3c7e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9536f828-4678-43b8-91f9-fcf3b41cb41c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_21d361a5-4718-4817-a6d2-000701db3c7e" xlink:to="loc_us-gaap_SegmentDomain_9536f828-4678-43b8-91f9-fcf3b41cb41c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosGovernmentSolutionsMember_a92ff0a1-6a7b-45e4-b795-ec2a8eea8c33" xlink:href="ktos-20220626.xsd#ktos_KratosGovernmentSolutionsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9536f828-4678-43b8-91f9-fcf3b41cb41c" xlink:to="loc_ktos_KratosGovernmentSolutionsMember_a92ff0a1-6a7b-45e4-b795-ec2a8eea8c33" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosUnmannedSystemsMember_23f208a5-cfe0-4150-ad56-86c9d93ee84a" xlink:href="ktos-20220626.xsd#ktos_KratosUnmannedSystemsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9536f828-4678-43b8-91f9-fcf3b41cb41c" xlink:to="loc_ktos_KratosUnmannedSystemsMember_23f208a5-cfe0-4150-ad56-86c9d93ee84a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_5f6e616c-e2dc-42f3-8e49-aee306676d89" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerBasisOfPricingAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_e6884934-8517-4878-9c9c-43178656b73a" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_5f6e616c-e2dc-42f3-8e49-aee306676d89" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_5f6e616c-e2dc-42f3-8e49-aee306676d89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_5f6e616c-e2dc-42f3-8e49-aee306676d89" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_5f6e616c-e2dc-42f3-8e49-aee306676d89_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_d5558cc2-4d40-4113-8267-fd2134e16760" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_5f6e616c-e2dc-42f3-8e49-aee306676d89" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_d5558cc2-4d40-4113-8267-fd2134e16760" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedPriceContractMember_5824865d-7ce1-4b9a-82a1-42e81e795dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FixedPriceContractMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_d5558cc2-4d40-4113-8267-fd2134e16760" xlink:to="loc_us-gaap_FixedPriceContractMember_5824865d-7ce1-4b9a-82a1-42e81e795dc6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_CostPlusFeeContractMember_ba7d06d8-70b4-47ae-b7b7-b86e77b97fd2" xlink:href="ktos-20220626.xsd#ktos_CostPlusFeeContractMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_d5558cc2-4d40-4113-8267-fd2134e16760" xlink:to="loc_ktos_CostPlusFeeContractMember_ba7d06d8-70b4-47ae-b7b7-b86e77b97fd2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeAndMaterialsContractMember_bfb19fae-96c2-4a8c-b5bb-08b67dd41c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimeAndMaterialsContractMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_d5558cc2-4d40-4113-8267-fd2134e16760" xlink:to="loc_us-gaap_TimeAndMaterialsContractMember_bfb19fae-96c2-4a8c-b5bb-08b67dd41c7e" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_0b88adbf-aaff-4ce1-900b-c4ef2a52d304" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_e6884934-8517-4878-9c9c-43178656b73a" xlink:to="loc_srt_MajorCustomersAxis_0b88adbf-aaff-4ce1-900b-c4ef2a52d304" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_0b88adbf-aaff-4ce1-900b-c4ef2a52d304_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_0b88adbf-aaff-4ce1-900b-c4ef2a52d304" xlink:to="loc_srt_NameOfMajorCustomerDomain_0b88adbf-aaff-4ce1-900b-c4ef2a52d304_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_08e84c96-740e-4e77-9b5e-1c04c933e466" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_0b88adbf-aaff-4ce1-900b-c4ef2a52d304" xlink:to="loc_srt_NameOfMajorCustomerDomain_08e84c96-740e-4e77-9b5e-1c04c933e466" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_UnitedStatesGovernmentMember_62175bab-4716-4b80-96d7-aab0e7fa05af" xlink:href="ktos-20220626.xsd#ktos_UnitedStatesGovernmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_08e84c96-740e-4e77-9b5e-1c04c933e466" xlink:to="loc_ktos_UnitedStatesGovernmentMember_62175bab-4716-4b80-96d7-aab0e7fa05af" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_NonUSGovernmentMember_5e74fec8-0d3d-4ca7-9f7f-d14dd920b431" xlink:href="ktos-20220626.xsd#ktos_NonUSGovernmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_08e84c96-740e-4e77-9b5e-1c04c933e466" xlink:to="loc_ktos_NonUSGovernmentMember_5e74fec8-0d3d-4ca7-9f7f-d14dd920b431" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_USCommercialMember_d17048f3-a259-40a3-8d6a-7c23afe4ddbf" xlink:href="ktos-20220626.xsd#ktos_USCommercialMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_08e84c96-740e-4e77-9b5e-1c04c933e466" xlink:to="loc_ktos_USCommercialMember_d17048f3-a259-40a3-8d6a-7c23afe4ddbf" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DiscontinuedOperationsDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#DiscontinuedOperationsDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DiscontinuedOperationsDetails" xlink:type="extended" id="i71b9800d0ad34147be65e736becc2434_DiscontinuedOperationsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c19559cc-8dd6-4947-997b-1b4320af96c4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_39c470af-158f-4f1b-9bda-aa1534a558f0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c19559cc-8dd6-4947-997b-1b4320af96c4" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_39c470af-158f-4f1b-9bda-aa1534a558f0" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_af7f1c2d-a43e-4fd2-8f2a-6b9525278ec1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c19559cc-8dd6-4947-997b-1b4320af96c4" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_af7f1c2d-a43e-4fd2-8f2a-6b9525278ec1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment_6d0a9b60-46ac-4e45-a5ac-7b17362d2265" xlink:href="ktos-20220626.xsd#ktos_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c19559cc-8dd6-4947-997b-1b4320af96c4" xlink:to="loc_ktos_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment_6d0a9b60-46ac-4e45-a5ac-7b17362d2265" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_b83ba59d-5c97-404b-8e89-ad0bbd32a426" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c19559cc-8dd6-4947-997b-1b4320af96c4" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_b83ba59d-5c97-404b-8e89-ad0bbd32a426" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_732fb480-cdf2-4af2-86c9-1b0f335d99f9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_b83ba59d-5c97-404b-8e89-ad0bbd32a426" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_732fb480-cdf2-4af2-86c9-1b0f335d99f9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_732fb480-cdf2-4af2-86c9-1b0f335d99f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_732fb480-cdf2-4af2-86c9-1b0f335d99f9" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_732fb480-cdf2-4af2-86c9-1b0f335d99f9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_04a86c50-f7ad-4cd2-aa15-bd3492953c83" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_732fb480-cdf2-4af2-86c9-1b0f335d99f9" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_04a86c50-f7ad-4cd2-aa15-bd3492953c83" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_PublicSafetyAndSecurityMember_c46939cf-007f-4a13-8f14-141599d3a6fd" xlink:href="ktos-20220626.xsd#ktos_PublicSafetyAndSecurityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_04a86c50-f7ad-4cd2-aa15-bd3492953c83" xlink:to="loc_ktos_PublicSafetyAndSecurityMember_c46939cf-007f-4a13-8f14-141599d3a6fd" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_26f1e406-4816-423e-8bc6-3a2218e76f77" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupClassificationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_b83ba59d-5c97-404b-8e89-ad0bbd32a426" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_26f1e406-4816-423e-8bc6-3a2218e76f77" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_26f1e406-4816-423e-8bc6-3a2218e76f77_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupClassificationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_26f1e406-4816-423e-8bc6-3a2218e76f77" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_26f1e406-4816-423e-8bc6-3a2218e76f77_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_e3fdeefb-7a88-4766-b247-53e41ae2e989" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupClassificationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_26f1e406-4816-423e-8bc6-3a2218e76f77" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_e3fdeefb-7a88-4766-b247-53e41ae2e989" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationsDisposedOfBySaleMember_e2dbb8b6-ca07-49dc-9b76-78d13edb9613" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DiscontinuedOperationsDisposedOfBySaleMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_e3fdeefb-7a88-4766-b247-53e41ae2e989" xlink:to="loc_us-gaap_DiscontinuedOperationsDisposedOfBySaleMember_e2dbb8b6-ca07-49dc-9b76-78d13edb9613" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/GoodwillandIntangibleAssetsGoodwillDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#GoodwillandIntangibleAssetsGoodwillDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/GoodwillandIntangibleAssetsGoodwillDetails" xlink:type="extended" id="idada799f469c4ea4bd4e50e62a0de28f_GoodwillandIntangibleAssetsGoodwillDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_a7c42cdb-068b-4b48-b455-dbd702cff25e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillGross_d16add9e-59de-4081-aaac-728f490ec3a3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_a7c42cdb-068b-4b48-b455-dbd702cff25e" xlink:to="loc_us-gaap_GoodwillGross_d16add9e-59de-4081-aaac-728f490ec3a3" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_80151ee4-dbd9-4b0f-be3c-2b67bc53f980" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_a7c42cdb-068b-4b48-b455-dbd702cff25e" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_80151ee4-dbd9-4b0f-be3c-2b67bc53f980" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01453786-3ad4-4cf1-ac5f-5b6a76fa6c27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_a7c42cdb-068b-4b48-b455-dbd702cff25e" xlink:to="loc_us-gaap_Goodwill_01453786-3ad4-4cf1-ac5f-5b6a76fa6c27" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_911073bb-c72e-482f-a4dc-6dadbb567764" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfGoodwillTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_a7c42cdb-068b-4b48-b455-dbd702cff25e" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_911073bb-c72e-482f-a4dc-6dadbb567764" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_0c308bb5-c7d7-43ff-949e-5ae9db4297db" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_911073bb-c72e-482f-a4dc-6dadbb567764" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_0c308bb5-c7d7-43ff-949e-5ae9db4297db" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_0c308bb5-c7d7-43ff-949e-5ae9db4297db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_0c308bb5-c7d7-43ff-949e-5ae9db4297db" xlink:to="loc_us-gaap_SegmentDomain_0c308bb5-c7d7-43ff-949e-5ae9db4297db_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_46375997-ef42-41e6-9e45-43d5be99717a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_0c308bb5-c7d7-43ff-949e-5ae9db4297db" xlink:to="loc_us-gaap_SegmentDomain_46375997-ef42-41e6-9e45-43d5be99717a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosGovernmentSolutionsMember_2ef1ce1a-d634-4ea6-808a-17ef9df1d59b" xlink:href="ktos-20220626.xsd#ktos_KratosGovernmentSolutionsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_46375997-ef42-41e6-9e45-43d5be99717a" xlink:to="loc_ktos_KratosGovernmentSolutionsMember_2ef1ce1a-d634-4ea6-808a-17ef9df1d59b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosUnmannedSystemsMember_ea77a5dd-5d1b-45f1-bb41-004571f228f9" xlink:href="ktos-20220626.xsd#ktos_KratosUnmannedSystemsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_46375997-ef42-41e6-9e45-43d5be99717a" xlink:to="loc_ktos_KratosUnmannedSystemsMember_ea77a5dd-5d1b-45f1-bb41-004571f228f9" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/GoodwillandIntangibleAssetsPurchasedIntangibleAssetsDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#GoodwillandIntangibleAssetsPurchasedIntangibleAssetsDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/GoodwillandIntangibleAssetsPurchasedIntangibleAssetsDetails" xlink:type="extended" id="i9a194fb14de44985af1ef86ad9f43210_GoodwillandIntangibleAssetsPurchasedIntangibleAssetsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_e08d1c24-6448-4e9f-ac65-f11689a3108e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_e08d1c24-6448-4e9f-ac65-f11689a3108e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_171e3645-8724-4940-bfc2-b2ca42066f65" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_171e3645-8724-4940-bfc2-b2ca42066f65" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_63b45ea5-bbd6-4d02-ab45-701a7d445669" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_63b45ea5-bbd6-4d02-ab45-701a7d445669" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_c14c4d0d-5773-4b4f-8357-503c0177fa54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_8d95db88-80ba-4c14-a5ca-4ddf6570caba" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_c14c4d0d-5773-4b4f-8357-503c0177fa54" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_IntangibleAssetsExcludingGoodwillGross_b8e710a0-08b4-4177-810b-b7bfed98e6e4" xlink:href="ktos-20220626.xsd#ktos_IntangibleAssetsExcludingGoodwillGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:to="loc_ktos_IntangibleAssetsExcludingGoodwillGross_b8e710a0-08b4-4177-810b-b7bfed98e6e4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_9d6bdee4-7ed1-4d46-b3c3-461e4b626f07" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_9d6bdee4-7ed1-4d46-b3c3-461e4b626f07" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_222d1987-b55f-4d70-aa02-d0b65ec3f69d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_222d1987-b55f-4d70-aa02-d0b65ec3f69d" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_42ad4488-17e4-41a0-938c-489daebbb21e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_76dff029-54ea-4687-bec8-a8d78ae662c2" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_42ad4488-17e4-41a0-938c-489daebbb21e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6ad61727-edf3-4330-829f-cfd877cab6f0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_42ad4488-17e4-41a0-938c-489daebbb21e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6ad61727-edf3-4330-829f-cfd877cab6f0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_6ad61727-edf3-4330-829f-cfd877cab6f0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6ad61727-edf3-4330-829f-cfd877cab6f0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_6ad61727-edf3-4330-829f-cfd877cab6f0_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6ad61727-edf3-4330-829f-cfd877cab6f0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_9e0134cc-fbc4-4993-872d-1061dafe1289" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:to="loc_us-gaap_CustomerRelationshipsMember_9e0134cc-fbc4-4993-872d-1061dafe1289" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ContractsAndBacklogMember_a5185565-6e50-48d5-a546-81b321596dfe" xlink:href="ktos-20220626.xsd#ktos_ContractsAndBacklogMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:to="loc_ktos_ContractsAndBacklogMember_a5185565-6e50-48d5-a546-81b321596dfe" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_13ae22db-ee37-4131-8424-c016dbf7ddc3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_13ae22db-ee37-4131-8424-c016dbf7ddc3" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_c6d4cf7c-c558-49b4-bbf3-a268daf45070" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TradeNamesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:to="loc_us-gaap_TradeNamesMember_c6d4cf7c-c558-49b4-bbf3-a268daf45070" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_ba14db65-a187-4866-a063-73728f40509e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InProcessResearchAndDevelopmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_337094e5-da30-4adf-9cbb-0d1f845d4667" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_ba14db65-a187-4866-a063-73728f40509e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a191c280-9fbe-4010-8e0a-666319cbb3f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_42ad4488-17e4-41a0-938c-489daebbb21e" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a191c280-9fbe-4010-8e0a-666319cbb3f3" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_a191c280-9fbe-4010-8e0a-666319cbb3f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a191c280-9fbe-4010-8e0a-666319cbb3f3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_a191c280-9fbe-4010-8e0a-666319cbb3f3_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_96d06c16-6e5f-4c5e-8949-3a27da5272b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a191c280-9fbe-4010-8e0a-666319cbb3f3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_96d06c16-6e5f-4c5e-8949-3a27da5272b6" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_b8b636a7-6065-4df0-bb62-a40dd7d39c27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TradeNamesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_96d06c16-6e5f-4c5e-8949-3a27da5272b6" xlink:to="loc_us-gaap_TradeNamesMember_b8b636a7-6065-4df0-bb62-a40dd7d39c27" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/NetIncomeLossperCommonShareDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#NetIncomeLossperCommonShareDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/NetIncomeLossperCommonShareDetails" xlink:type="extended" id="i9c1956acc3204c04b484b908af33a9c8_NetIncomeLossperCommonShareDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_500c2822-70f0-4eb1-8528-0edd212e3c57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_1c60647e-d3fa-471d-aa64-b5da43d8aa65" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_500c2822-70f0-4eb1-8528-0edd212e3c57" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_1c60647e-d3fa-471d-aa64-b5da43d8aa65" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fedafbc2-ce90-4e61-9cad-bd0d92aaa3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_500c2822-70f0-4eb1-8528-0edd212e3c57" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fedafbc2-ce90-4e61-9cad-bd0d92aaa3e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_11e13821-a030-48ba-ac8a-0ebb94767b3e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fedafbc2-ce90-4e61-9cad-bd0d92aaa3e5" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_11e13821-a030-48ba-ac8a-0ebb94767b3e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_11e13821-a030-48ba-ac8a-0ebb94767b3e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_11e13821-a030-48ba-ac8a-0ebb94767b3e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_11e13821-a030-48ba-ac8a-0ebb94767b3e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8c6ad5ba-bc8c-4148-b43d-de6ca0378fa4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_11e13821-a030-48ba-ac8a-0ebb94767b3e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8c6ad5ba-bc8c-4148-b43d-de6ca0378fa4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_StockOptionsAndStockAwardsMember_156aee8d-688f-4b84-9729-a41046d90c1f" xlink:href="ktos-20220626.xsd#ktos_StockOptionsAndStockAwardsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8c6ad5ba-bc8c-4148-b43d-de6ca0378fa4" xlink:to="loc_ktos_StockOptionsAndStockAwardsMember_156aee8d-688f-4b84-9729-a41046d90c1f" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DebtNewCreditFacilityDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#DebtNewCreditFacilityDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DebtNewCreditFacilityDetails" xlink:type="extended" id="icc3e54cf5c5d4a15bfbe13930be7f106_DebtNewCreditFacilityDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_7bcd5134-138c-48a6-b531-ee464611a6b0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCredit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_LineOfCredit_7bcd5134-138c-48a6-b531-ee464611a6b0" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_07e8e218-0264-43aa-8f7b-a9f4db0b87a8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_LongTermDebt_07e8e218-0264-43aa-8f7b-a9f4db0b87a8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_e9fe2cba-50a0-4e40-8ec8-56de74125452" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_e9fe2cba-50a0-4e40-8ec8-56de74125452" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_707a62c6-81d3-4505-b1b8-b6e482524bca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTerm"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentTerm_707a62c6-81d3-4505-b1b8-b6e482524bca" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_27d5af3e-cd28-4693-9253-25b8880f87a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_27d5af3e-cd28-4693-9253-25b8880f87a7" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_67a60094-0200-4130-86dc-49d339fc2b2e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_67a60094-0200-4130-86dc-49d339fc2b2e" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_64ad7e9c-be34-4331-863c-5f2850b2afbc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromLinesOfCredit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_64ad7e9c-be34-4331-863c-5f2850b2afbc" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_35445bbd-517e-4ff6-947b-1437e498bd7c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_35445bbd-517e-4ff6-947b-1437e498bd7c" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_169083bb-17fc-47a5-abc9-a8f70dbdc164" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_169083bb-17fc-47a5-abc9-a8f70dbdc164" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_DebtInstrumentPremiumRedemptionPricePercentage_ea94153b-1ace-4d6b-b853-6f8b3f4ebea5" xlink:href="ktos-20220626.xsd#ktos_DebtInstrumentPremiumRedemptionPricePercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_ktos_DebtInstrumentPremiumRedemptionPricePercentage_ea94153b-1ace-4d6b-b853-6f8b3f4ebea5" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_84acbb24-7fb0-46a8-a2bd-e0c548491041" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_84acbb24-7fb0-46a8-a2bd-e0c548491041" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_33efc817-bf03-42b2-b346-a6b6770dff24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_33efc817-bf03-42b2-b346-a6b6770dff24" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium_0ef3240f-b49a-4b6e-9e74-616398af6656" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedPremium"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedPremium_0ef3240f-b49a-4b6e-9e74-616398af6656" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_195628d6-abbe-40e4-8406-01016a79c0f7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_195628d6-abbe-40e4-8406-01016a79c0f7" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_6a58933a-1a5a-45d5-bfe7-885a3577b2a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_6a58933a-1a5a-45d5-bfe7-885a3577b2a2" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_651b4462-9f75-40e4-a832-6604144d15ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_651b4462-9f75-40e4-a832-6604144d15ec" xlink:type="arc" order="15"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_a0ff72ae-0f2a-4bbb-aae6-2e0c5b8d58a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_a0ff72ae-0f2a-4bbb-aae6-2e0c5b8d58a2" xlink:type="arc" order="16"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_LineOfCreditAmortizationPercentage_6b7fa909-0db6-4bca-9d3b-6a9735d733d8" xlink:href="ktos-20220626.xsd#ktos_LineOfCreditAmortizationPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_ktos_LineOfCreditAmortizationPercentage_6b7fa909-0db6-4bca-9d3b-6a9735d733d8" xlink:type="arc" order="17"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_718b5cb1-b973-4c8f-a749-7cab3ce5fdca" xlink:to="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_fce4371b-eb71-442c-84dd-90c4e4b34e6f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_us-gaap_CreditFacilityAxis_fce4371b-eb71-442c-84dd-90c4e4b34e6f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_fce4371b-eb71-442c-84dd-90c4e4b34e6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_fce4371b-eb71-442c-84dd-90c4e4b34e6f" xlink:to="loc_us-gaap_CreditFacilityDomain_fce4371b-eb71-442c-84dd-90c4e4b34e6f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_fce4371b-eb71-442c-84dd-90c4e4b34e6f" xlink:to="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_018695a2-e974-4bc5-8163-d5600d708347" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_018695a2-e974-4bc5-8163-d5600d708347" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_3488adb2-5e61-4dcc-9fae-37965e5f54a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:to="loc_us-gaap_SecuredDebtMember_3488adb2-5e61-4dcc-9fae-37965e5f54a2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_SwingLineLoanMember_81fb29f0-d380-4441-9e2c-80764cc2294e" xlink:href="ktos-20220626.xsd#ktos_SwingLineLoanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:to="loc_ktos_SwingLineLoanMember_81fb29f0-d380-4441-9e2c-80764cc2294e" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_b9f706af-61df-47c9-9828-a04dbfce7b2a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LetterOfCreditMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_60773646-fbe9-4b04-85c4-22a1f0ad169f" xlink:to="loc_us-gaap_LetterOfCreditMember_b9f706af-61df-47c9-9828-a04dbfce7b2a" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_a1f10ee4-5952-4455-94b0-89a49e0004dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_us-gaap_DebtInstrumentAxis_a1f10ee4-5952-4455-94b0-89a49e0004dc" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a1f10ee4-5952-4455-94b0-89a49e0004dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_a1f10ee4-5952-4455-94b0-89a49e0004dc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a1f10ee4-5952-4455-94b0-89a49e0004dc_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_a1f10ee4-5952-4455-94b0-89a49e0004dc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member_2bcd7ff1-9953-458c-bdb4-ae66166347d2" xlink:href="ktos-20220626.xsd#ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:to="loc_ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member_2bcd7ff1-9953-458c-bdb4-ae66166347d2" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_NewRevolvingCreditFacilityMember_f8d81128-807e-4d4a-bdc0-9377535ebf6d" xlink:href="ktos-20220626.xsd#ktos_NewRevolvingCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:to="loc_ktos_NewRevolvingCreditFacilityMember_f8d81128-807e-4d4a-bdc0-9377535ebf6d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_TermLoanAMember_3ad16093-d37a-4e8d-bc45-95f5b4925e65" xlink:href="ktos-20220626.xsd#ktos_TermLoanAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:to="loc_ktos_TermLoanAMember_3ad16093-d37a-4e8d-bc45-95f5b4925e65" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_NewCreditFacilityMember_febf9889-1c2c-4ab5-9bf5-6abfd22ab510" xlink:href="ktos-20220626.xsd#ktos_NewCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1544a093-71f1-423b-b155-0dcbd8c643a6" xlink:to="loc_ktos_NewCreditFacilityMember_febf9889-1c2c-4ab5-9bf5-6abfd22ab510" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_8a14e0b0-d6ec-47da-8946-570d0dc90089" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_8a14e0b0-d6ec-47da-8946-570d0dc90089" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_8a14e0b0-d6ec-47da-8946-570d0dc90089_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_8a14e0b0-d6ec-47da-8946-570d0dc90089" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_8a14e0b0-d6ec-47da-8946-570d0dc90089_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_41188122-2fee-4e96-aef1-4a6d4e3bcfb5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_8a14e0b0-d6ec-47da-8946-570d0dc90089" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_41188122-2fee-4e96-aef1-4a6d4e3bcfb5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_564cbfc4-3aeb-4678-a244-0e55d20a9012" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_41188122-2fee-4e96-aef1-4a6d4e3bcfb5" xlink:to="loc_us-gaap_SeniorNotesMember_564cbfc4-3aeb-4678-a244-0e55d20a9012" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_9e5b8da0-a3f9-49d4-b87d-268b29c6916b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_us-gaap_VariableRateAxis_9e5b8da0-a3f9-49d4-b87d-268b29c6916b" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_9e5b8da0-a3f9-49d4-b87d-268b29c6916b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_9e5b8da0-a3f9-49d4-b87d-268b29c6916b" xlink:to="loc_us-gaap_VariableRateDomain_9e5b8da0-a3f9-49d4-b87d-268b29c6916b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_13a2ac60-1775-4952-a901-a69b178a7ec8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_9e5b8da0-a3f9-49d4-b87d-268b29c6916b" xlink:to="loc_us-gaap_VariableRateDomain_13a2ac60-1775-4952-a901-a69b178a7ec8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_651e3ed5-25d3-4e2d-80a2-a3207b3a5a25" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_13a2ac60-1775-4952-a901-a69b178a7ec8" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_651e3ed5-25d3-4e2d-80a2-a3207b3a5a25" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_4b098ee7-fad4-4347-a314-f387a4a94fcd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BaseRateMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_13a2ac60-1775-4952-a901-a69b178a7ec8" xlink:to="loc_us-gaap_BaseRateMember_4b098ee7-fad4-4347-a314-f387a4a94fcd" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_cce846d5-5464-4b88-a496-d8c1b8ff4c92" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_srt_RangeAxis_cce846d5-5464-4b88-a496-d8c1b8ff4c92" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_cce846d5-5464-4b88-a496-d8c1b8ff4c92_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_cce846d5-5464-4b88-a496-d8c1b8ff4c92" xlink:to="loc_srt_RangeMember_cce846d5-5464-4b88-a496-d8c1b8ff4c92_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_db61a3b1-aaac-4426-9906-8eae2c735618" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_cce846d5-5464-4b88-a496-d8c1b8ff4c92" xlink:to="loc_srt_RangeMember_db61a3b1-aaac-4426-9906-8eae2c735618" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_8c3047f6-f3a8-4c18-ac14-5484dfde93dc" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_db61a3b1-aaac-4426-9906-8eae2c735618" xlink:to="loc_srt_MinimumMember_8c3047f6-f3a8-4c18-ac14-5484dfde93dc" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_ff691eb9-4036-49d5-ac55-e756b0451d0d" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_db61a3b1-aaac-4426-9906-8eae2c735618" xlink:to="loc_srt_MaximumMember_ff691eb9-4036-49d5-ac55-e756b0451d0d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_AmortizationPeriodAxis_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9" xlink:href="ktos-20220626.xsd#ktos_AmortizationPeriodAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9c9546b3-ced7-46b6-872e-3a074ab92f5c" xlink:to="loc_ktos_AmortizationPeriodAxis_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_AmortizationPeriodDomain_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9_default" xlink:href="ktos-20220626.xsd#ktos_AmortizationPeriodDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ktos_AmortizationPeriodAxis_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9" xlink:to="loc_ktos_AmortizationPeriodDomain_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_AmortizationPeriodDomain_9841ceee-36d1-4f40-8b30-cd4acb297c31" xlink:href="ktos-20220626.xsd#ktos_AmortizationPeriodDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ktos_AmortizationPeriodAxis_7e31d493-4f78-447d-b3dd-e6e5d6b97fb9" xlink:to="loc_ktos_AmortizationPeriodDomain_9841ceee-36d1-4f40-8b30-cd4acb297c31" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_FirstAndSecondYearMember_434d7e09-b023-4220-81e5-2da1d4a440c7" xlink:href="ktos-20220626.xsd#ktos_FirstAndSecondYearMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ktos_AmortizationPeriodDomain_9841ceee-36d1-4f40-8b30-cd4acb297c31" xlink:to="loc_ktos_FirstAndSecondYearMember_434d7e09-b023-4220-81e5-2da1d4a440c7" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_ThirdFourthAndFifthYearMember_205ce802-a279-4e86-9f9b-cdd567e9b6a5" xlink:href="ktos-20220626.xsd#ktos_ThirdFourthAndFifthYearMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ktos_AmortizationPeriodDomain_9841ceee-36d1-4f40-8b30-cd4acb297c31" xlink:to="loc_ktos_ThirdFourthAndFifthYearMember_205ce802-a279-4e86-9f9b-cdd567e9b6a5" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DebtLongTermDebtandtheCurrentPeriodInterestRatesDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#DebtLongTermDebtandtheCurrentPeriodInterestRatesDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DebtLongTermDebtandtheCurrentPeriodInterestRatesDetails" xlink:type="extended" id="i3509547aed30441ebc3631fd42dba35d_DebtLongTermDebtandtheCurrentPeriodInterestRatesDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_e0d070cd-dd0a-4e5a-af28-7314a2c7ee9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_e0d070cd-dd0a-4e5a-af28-7314a2c7ee9f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_LongTermDebtCurrentMaturitiesGross_a1a13158-5c01-4f4f-ba47-950d660ce827" xlink:href="ktos-20220626.xsd#ktos_LongTermDebtCurrentMaturitiesGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_ktos_LongTermDebtCurrentMaturitiesGross_a1a13158-5c01-4f4f-ba47-950d660ce827" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_LongTermDebtExcludingCurrentMaturitiesGross_9d1d66fc-8c7f-4e07-ba74-8b58e4db96a4" xlink:href="ktos-20220626.xsd#ktos_LongTermDebtExcludingCurrentMaturitiesGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_ktos_LongTermDebtExcludingCurrentMaturitiesGross_9d1d66fc-8c7f-4e07-ba74-8b58e4db96a4" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_2304f825-02bb-4041-95cb-04e8e888e5ce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_2304f825-02bb-4041-95cb-04e8e888e5ce" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_f26a8a55-9a4f-42e3-a9e0-82b2b139c7dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_us-gaap_LongTermDebt_f26a8a55-9a4f-42e3-a9e0-82b2b139c7dd" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_1dcce96d-c9d4-41ba-a185-844e372af16e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_1dcce96d-c9d4-41ba-a185-844e372af16e" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_4124c99b-9471-41fa-8537-3f753170c2cf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_b2fd7612-ef7e-403f-a32a-ab7c04d2b864" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_4124c99b-9471-41fa-8537-3f753170c2cf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_90fd0ea6-4bce-4265-87af-1839c390378f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_4124c99b-9471-41fa-8537-3f753170c2cf" xlink:to="loc_us-gaap_CreditFacilityAxis_90fd0ea6-4bce-4265-87af-1839c390378f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_90fd0ea6-4bce-4265-87af-1839c390378f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_90fd0ea6-4bce-4265-87af-1839c390378f" xlink:to="loc_us-gaap_CreditFacilityDomain_90fd0ea6-4bce-4265-87af-1839c390378f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_7208ea11-e402-42ea-99c9-06cb1fe25281" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_90fd0ea6-4bce-4265-87af-1839c390378f" xlink:to="loc_us-gaap_CreditFacilityDomain_7208ea11-e402-42ea-99c9-06cb1fe25281" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_a41255e1-4b4e-4c41-8311-ddc9f8babb8d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7208ea11-e402-42ea-99c9-06cb1fe25281" xlink:to="loc_us-gaap_SecuredDebtMember_a41255e1-4b4e-4c41-8311-ddc9f8babb8d" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_87f6e318-93c3-4d56-bd45-983e4f365545" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7208ea11-e402-42ea-99c9-06cb1fe25281" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_87f6e318-93c3-4d56-bd45-983e4f365545" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_7b083d23-5b1c-40bc-99fd-21ecee32f7e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_4124c99b-9471-41fa-8537-3f753170c2cf" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_7b083d23-5b1c-40bc-99fd-21ecee32f7e5" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7b083d23-5b1c-40bc-99fd-21ecee32f7e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_7b083d23-5b1c-40bc-99fd-21ecee32f7e5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7b083d23-5b1c-40bc-99fd-21ecee32f7e5_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c1799fcf-f09a-4c5c-9f17-bc114035cc90" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_7b083d23-5b1c-40bc-99fd-21ecee32f7e5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c1799fcf-f09a-4c5c-9f17-bc114035cc90" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_13c24222-3f35-48b2-ba61-927bb3ca6e65" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c1799fcf-f09a-4c5c-9f17-bc114035cc90" xlink:to="loc_us-gaap_LineOfCreditMember_13c24222-3f35-48b2-ba61-927bb3ca6e65" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DebtFutureLongTermDebtPrincipalPaymentsDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#DebtFutureLongTermDebtPrincipalPaymentsDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DebtFutureLongTermDebtPrincipalPaymentsDetails" xlink:type="extended" id="id5ee0369b23d442f819c2e587d2b0c89_DebtFutureLongTermDebtPrincipalPaymentsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_990b5f73-8c80-4938-a21a-ddf0b6cf9dc5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_990b5f73-8c80-4938-a21a-ddf0b6cf9dc5" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_bc675884-6284-4d63-a58a-c8c07b03f2c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_bc675884-6284-4d63-a58a-c8c07b03f2c0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_cdb7042b-65c1-4f4d-974b-a28becdf4a85" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_cdb7042b-65c1-4f4d-974b-a28becdf4a85" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_aae11af3-7e2e-462f-b7ac-5f181b327476" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_aae11af3-7e2e-462f-b7ac-5f181b327476" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_d596a566-4f8d-4daf-a0e1-998171640154" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_d596a566-4f8d-4daf-a0e1-998171640154" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_5c7f981b-6501-416e-8cf2-ac46e1d457ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_5c7f981b-6501-416e-8cf2-ac46e1d457ae" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_702d82df-50c0-4ba4-8f83-7a071723e475" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_702d82df-50c0-4ba4-8f83-7a071723e475" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3863c25d-03f4-427e-8df6-31a0d9858ac5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_992c1e92-f24b-4481-8c9f-fa329db72365" xlink:to="loc_us-gaap_DebtInstrumentTable_3863c25d-03f4-427e-8df6-31a0d9858ac5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3863c25d-03f4-427e-8df6-31a0d9858ac5" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_6ebd058c-7834-4642-92e1-53d43c55fdd2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c8ddd89d-b53b-4ca4-b108-43bcd9f7e7b4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_6ebd058c-7834-4642-92e1-53d43c55fdd2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_e7f11821-edad-4bad-ac87-e7b2e02264e9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_6ebd058c-7834-4642-92e1-53d43c55fdd2" xlink:to="loc_us-gaap_SecuredDebtMember_e7f11821-edad-4bad-ac87-e7b2e02264e9" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_9cf8c325-112e-4d49-bf81-ba7627ed8e6f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3863c25d-03f4-427e-8df6-31a0d9858ac5" xlink:to="loc_us-gaap_CreditFacilityAxis_9cf8c325-112e-4d49-bf81-ba7627ed8e6f" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_9cf8c325-112e-4d49-bf81-ba7627ed8e6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_9cf8c325-112e-4d49-bf81-ba7627ed8e6f" xlink:to="loc_us-gaap_CreditFacilityDomain_9cf8c325-112e-4d49-bf81-ba7627ed8e6f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_9a56dc0b-0a86-4fc6-8a59-a93a44a1f1b3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_9cf8c325-112e-4d49-bf81-ba7627ed8e6f" xlink:to="loc_us-gaap_CreditFacilityDomain_9a56dc0b-0a86-4fc6-8a59-a93a44a1f1b3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_b3a360d9-1f0a-46d2-92dd-95e6cc10c607" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_9a56dc0b-0a86-4fc6-8a59-a93a44a1f1b3" xlink:to="loc_us-gaap_LineOfCreditMember_b3a360d9-1f0a-46d2-92dd-95e6cc10c607" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DebtIssuanceof65SeniorSecuredNotesdue2025Details" xlink:type="simple" xlink:href="ktos-20220626.xsd#DebtIssuanceof65SeniorSecuredNotesdue2025Details"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DebtIssuanceof65SeniorSecuredNotesdue2025Details" xlink:type="extended" id="ib8bf6172f49649589344ae5a0b46baa1_DebtIssuanceof65SeniorSecuredNotesdue2025Details">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_dfa37899-eb89-45b8-9698-188e6a70c0a5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_f9de272a-5b57-4d15-88f9-ce5eb25aa03d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_dfa37899-eb89-45b8-9698-188e6a70c0a5" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_f9de272a-5b57-4d15-88f9-ce5eb25aa03d" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_22d359b7-543f-4857-8a68-9ecd5eae70bd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_dfa37899-eb89-45b8-9698-188e6a70c0a5" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_22d359b7-543f-4857-8a68-9ecd5eae70bd" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_977c75a0-d3c8-4487-8a9e-c15eaeca990a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_dfa37899-eb89-45b8-9698-188e6a70c0a5" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_977c75a0-d3c8-4487-8a9e-c15eaeca990a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_6fb6c670-bbdb-457a-9d04-294cd0e32f23" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_dfa37899-eb89-45b8-9698-188e6a70c0a5" xlink:to="loc_us-gaap_DebtInstrumentTable_6fb6c670-bbdb-457a-9d04-294cd0e32f23" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_5ed91c5a-ab03-4403-9dac-87dac3e35411" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6fb6c670-bbdb-457a-9d04-294cd0e32f23" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_5ed91c5a-ab03-4403-9dac-87dac3e35411" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5ed91c5a-ab03-4403-9dac-87dac3e35411_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5ed91c5a-ab03-4403-9dac-87dac3e35411" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5ed91c5a-ab03-4403-9dac-87dac3e35411_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ca2a7cc5-0b1f-440d-863b-b94bcff2f955" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5ed91c5a-ab03-4403-9dac-87dac3e35411" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ca2a7cc5-0b1f-440d-863b-b94bcff2f955" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_5c220989-d9f6-453a-b15e-e7a03cd0d9dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ca2a7cc5-0b1f-440d-863b-b94bcff2f955" xlink:to="loc_us-gaap_SeniorNotesMember_5c220989-d9f6-453a-b15e-e7a03cd0d9dc" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_1305bdac-2df2-4620-9a10-a257fc0b0d1f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6fb6c670-bbdb-457a-9d04-294cd0e32f23" xlink:to="loc_us-gaap_DebtInstrumentAxis_1305bdac-2df2-4620-9a10-a257fc0b0d1f" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1305bdac-2df2-4620-9a10-a257fc0b0d1f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_1305bdac-2df2-4620-9a10-a257fc0b0d1f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1305bdac-2df2-4620-9a10-a257fc0b0d1f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_68574c0e-c5f0-451a-aa1f-03c3956154b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_1305bdac-2df2-4620-9a10-a257fc0b0d1f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_68574c0e-c5f0-451a-aa1f-03c3956154b6" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member_c6da4271-b8a6-4ad5-91e7-47bc0e24b7ad" xlink:href="ktos-20220626.xsd#ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_68574c0e-c5f0-451a-aa1f-03c3956154b6" xlink:to="loc_ktos_SixPointFivePercentSeniorSecuredNotesDue2025Member_c6da4271-b8a6-4ad5-91e7-47bc0e24b7ad" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/DebtOtherIndebtednessDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#DebtOtherIndebtednessDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/DebtOtherIndebtednessDetails" xlink:type="extended" id="i4cc2ab213185442fab82b319a550b1a8_DebtOtherIndebtednessDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_f29f3bf8-d74e-4313-bc71-b3e417e7658d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTerm"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_DebtInstrumentTerm_f29f3bf8-d74e-4313-bc71-b3e417e7658d" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_e6aa54c1-cf9d-4024-895e-fa320042dfd8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_e6aa54c1-cf9d-4024-895e-fa320042dfd8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_df03b11b-3cac-4516-aa41-3fbf87a4b4d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_LongTermDebt_df03b11b-3cac-4516-aa41-3fbf87a4b4d6" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_0aee6d88-d633-496d-a832-6a9ed39082f9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_0aee6d88-d633-496d-a832-6a9ed39082f9" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_53d165e8-7c9b-408c-92f4-e17f8182225d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_53d165e8-7c9b-408c-92f4-e17f8182225d" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_b04e126b-aa6b-4505-9d25-955b647269b2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_8e2a2fb5-84c3-4fd0-aa42-1336d0f1f94c" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_b04e126b-aa6b-4505-9d25-955b647269b2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_e0b3ac32-a16b-4a59-86b7-e05131510538" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_b04e126b-aa6b-4505-9d25-955b647269b2" xlink:to="loc_us-gaap_CreditFacilityAxis_e0b3ac32-a16b-4a59-86b7-e05131510538" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_e0b3ac32-a16b-4a59-86b7-e05131510538_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_e0b3ac32-a16b-4a59-86b7-e05131510538" xlink:to="loc_us-gaap_CreditFacilityDomain_e0b3ac32-a16b-4a59-86b7-e05131510538_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_7efc330b-54b5-425b-a399-565f94d45008" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_e0b3ac32-a16b-4a59-86b7-e05131510538" xlink:to="loc_us-gaap_CreditFacilityDomain_7efc330b-54b5-425b-a399-565f94d45008" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_aa841a41-3835-446a-bbe0-da83fa1ac4f7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7efc330b-54b5-425b-a399-565f94d45008" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_aa841a41-3835-446a-bbe0-da83fa1ac4f7" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_15e7130a-ae61-4662-b1f5-5da133551e17" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LetterOfCreditMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7efc330b-54b5-425b-a399-565f94d45008" xlink:to="loc_us-gaap_LetterOfCreditMember_15e7130a-ae61-4662-b1f5-5da133551e17" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_SwingLineLoanMember_11b87f1a-c6b3-483e-90a7-e101032d43ff" xlink:href="ktos-20220626.xsd#ktos_SwingLineLoanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7efc330b-54b5-425b-a399-565f94d45008" xlink:to="loc_ktos_SwingLineLoanMember_11b87f1a-c6b3-483e-90a7-e101032d43ff" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/SegmentInformationNarrativeDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#SegmentInformationNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/SegmentInformationNarrativeDetails" xlink:type="extended" id="ib0adc6778452421d8f878fc895539bf7_SegmentInformationNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_007f3125-5426-4c87-8d39-1fd5bad7b6f2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_25b04d9f-a445-4024-b790-78fdf944c9e6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfReportableSegments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_007f3125-5426-4c87-8d39-1fd5bad7b6f2" xlink:to="loc_us-gaap_NumberOfReportableSegments_25b04d9f-a445-4024-b790-78fdf944c9e6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_9c9dda7b-a55c-445b-ad9a-224c7c7f14f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_007f3125-5426-4c87-8d39-1fd5bad7b6f2" xlink:to="loc_us-gaap_LitigationSettlementExpense_9c9dda7b-a55c-445b-ad9a-224c7c7f14f3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ac345441-99a7-40f1-bbe0-509ed42f4d68" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_007f3125-5426-4c87-8d39-1fd5bad7b6f2" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ac345441-99a7-40f1-bbe0-509ed42f4d68" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_44673433-7a80-4b50-b71d-2a8c0fbc8845" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ac345441-99a7-40f1-bbe0-509ed42f4d68" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_44673433-7a80-4b50-b71d-2a8c0fbc8845" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_44673433-7a80-4b50-b71d-2a8c0fbc8845_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_44673433-7a80-4b50-b71d-2a8c0fbc8845" xlink:to="loc_us-gaap_SegmentDomain_44673433-7a80-4b50-b71d-2a8c0fbc8845_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d5731da4-f2f7-4f20-9601-c4273ec3ba33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_44673433-7a80-4b50-b71d-2a8c0fbc8845" xlink:to="loc_us-gaap_SegmentDomain_d5731da4-f2f7-4f20-9601-c4273ec3ba33" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosUnmannedSystemsMember_c43a7e2e-9880-466a-b2e9-43ec93fd32dd" xlink:href="ktos-20220626.xsd#ktos_KratosUnmannedSystemsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d5731da4-f2f7-4f20-9601-c4273ec3ba33" xlink:to="loc_ktos_KratosUnmannedSystemsMember_c43a7e2e-9880-466a-b2e9-43ec93fd32dd" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/SegmentInformationScheduleofSegmentRevenuesDepreciationandAmortizationandOperatingLossDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#SegmentInformationScheduleofSegmentRevenuesDepreciationandAmortizationandOperatingLossDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/SegmentInformationScheduleofSegmentRevenuesDepreciationandAmortizationandOperatingLossDetails" xlink:type="extended" id="i53ef9b97cbef48179c6a0446eb43fd09_SegmentInformationScheduleofSegmentRevenuesDepreciationandAmortizationandOperatingLossDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_6b3b220f-094f-4901-9799-1caf99ba4d62" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_54331940-339f-4bcc-8449-43f602b6ec59" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6b3b220f-094f-4901-9799-1caf99ba4d62" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_54331940-339f-4bcc-8449-43f602b6ec59" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortizationNonproductionAbstract_051aa06b-71d5-468c-a721-c7cd6fff46c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepreciationDepletionAndAmortizationNonproductionAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6b3b220f-094f-4901-9799-1caf99ba4d62" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortizationNonproductionAbstract_051aa06b-71d5-468c-a721-c7cd6fff46c0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_4b147164-ce7c-45e9-9db8-5d16ab7134d7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepreciationDepletionAndAmortizationNonproductionAbstract_051aa06b-71d5-468c-a721-c7cd6fff46c0" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_4b147164-ce7c-45e9-9db8-5d16ab7134d7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLossAbstract_9d69578c-3382-4e1f-9241-467c1b7bf650" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLossAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6b3b220f-094f-4901-9799-1caf99ba4d62" xlink:to="loc_us-gaap_OperatingIncomeLossAbstract_9d69578c-3382-4e1f-9241-467c1b7bf650" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_4be423ee-56a3-4fd7-945e-f659566f10d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingIncomeLossAbstract_9d69578c-3382-4e1f-9241-467c1b7bf650" xlink:to="loc_us-gaap_OperatingIncomeLoss_4be423ee-56a3-4fd7-945e-f659566f10d2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4b3bbc45-0cb4-4cf4-9bc9-1c124f3e9040" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6b3b220f-094f-4901-9799-1caf99ba4d62" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4b3bbc45-0cb4-4cf4-9bc9-1c124f3e9040" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_350e4072-5503-43ec-be23-ff08063c361b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4b3bbc45-0cb4-4cf4-9bc9-1c124f3e9040" xlink:to="loc_srt_ProductOrServiceAxis_350e4072-5503-43ec-be23-ff08063c361b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_350e4072-5503-43ec-be23-ff08063c361b_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_350e4072-5503-43ec-be23-ff08063c361b" xlink:to="loc_srt_ProductsAndServicesDomain_350e4072-5503-43ec-be23-ff08063c361b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_a4773d7a-f378-4148-a813-2607b964dcbb" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_350e4072-5503-43ec-be23-ff08063c361b" xlink:to="loc_srt_ProductsAndServicesDomain_a4773d7a-f378-4148-a813-2607b964dcbb" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_a424938b-b598-47e1-b1ca-1d3783da1e47" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ServiceMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a4773d7a-f378-4148-a813-2607b964dcbb" xlink:to="loc_us-gaap_ServiceMember_a424938b-b598-47e1-b1ca-1d3783da1e47" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_414aab04-2fcc-4a8c-a4ce-1107d896d36c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a4773d7a-f378-4148-a813-2607b964dcbb" xlink:to="loc_us-gaap_ProductMember_414aab04-2fcc-4a8c-a4ce-1107d896d36c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2fcf4137-d32f-4919-a453-5287384fa287" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4b3bbc45-0cb4-4cf4-9bc9-1c124f3e9040" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2fcf4137-d32f-4919-a453-5287384fa287" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_2fcf4137-d32f-4919-a453-5287384fa287_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2fcf4137-d32f-4919-a453-5287384fa287" xlink:to="loc_us-gaap_SegmentDomain_2fcf4137-d32f-4919-a453-5287384fa287_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_69858d5c-2ddf-470f-80fc-19ce2e59b1be" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2fcf4137-d32f-4919-a453-5287384fa287" xlink:to="loc_us-gaap_SegmentDomain_69858d5c-2ddf-470f-80fc-19ce2e59b1be" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosGovernmentSolutionsMember_c9e16b9a-cca3-431a-a911-9b8e05368668" xlink:href="ktos-20220626.xsd#ktos_KratosGovernmentSolutionsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_69858d5c-2ddf-470f-80fc-19ce2e59b1be" xlink:to="loc_ktos_KratosGovernmentSolutionsMember_c9e16b9a-cca3-431a-a911-9b8e05368668" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KratosUnmannedSystemsMember_7047d697-8d28-4ace-97fa-9d284ef94dcf" xlink:href="ktos-20220626.xsd#ktos_KratosUnmannedSystemsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_69858d5c-2ddf-470f-80fc-19ce2e59b1be" xlink:to="loc_ktos_KratosUnmannedSystemsMember_7047d697-8d28-4ace-97fa-9d284ef94dcf" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_6281416d-fdbe-4bb9-8289-f1e0afb27866" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4b3bbc45-0cb4-4cf4-9bc9-1c124f3e9040" xlink:to="loc_srt_ConsolidationItemsAxis_6281416d-fdbe-4bb9-8289-f1e0afb27866" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_6281416d-fdbe-4bb9-8289-f1e0afb27866_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_6281416d-fdbe-4bb9-8289-f1e0afb27866" xlink:to="loc_srt_ConsolidationItemsDomain_6281416d-fdbe-4bb9-8289-f1e0afb27866_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_529b97aa-0508-48ba-b4e3-64b9acdec827" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_6281416d-fdbe-4bb9-8289-f1e0afb27866" xlink:to="loc_srt_ConsolidationItemsDomain_529b97aa-0508-48ba-b4e3-64b9acdec827" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_4ca2b093-ec42-4111-9b55-f848e575703c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_529b97aa-0508-48ba-b4e3-64b9acdec827" xlink:to="loc_us-gaap_OperatingSegmentsMember_4ca2b093-ec42-4111-9b55-f848e575703c" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_c06e151f-ad4a-4481-b040-2c285290dd4d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CorporateNonSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_529b97aa-0508-48ba-b4e3-64b9acdec827" xlink:to="loc_us-gaap_CorporateNonSegmentMember_c06e151f-ad4a-4481-b040-2c285290dd4d" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/RedeemableNoncontrollingInterestDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#RedeemableNoncontrollingInterestDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/RedeemableNoncontrollingInterestDetails" xlink:type="extended" id="ide8f79756ca74f128f18d95d3deace17_RedeemableNoncontrollingInterestDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_45059172-b6e5-429a-a5cd-dcf146e9e743" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_45059172-b6e5-429a-a5cd-dcf146e9e743" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_e3c33ddc-0f50-4921-a1d1-e978d7873da8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_e3c33ddc-0f50-4921-a1d1-e978d7873da8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_97317399-9a41-485a-a1c0-f5669c988d49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_97317399-9a41-485a-a1c0-f5669c988d49" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_824dee47-1daf-41a6-95f9-642d219f211f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_824dee47-1daf-41a6-95f9-642d219f211f" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_e6d48679-45a4-496d-b144-a0174863472c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_e6d48679-45a4-496d-b144-a0174863472c" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_3ebe816f-1690-4661-923a-1a3bb4949a13" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_3ebe816f-1690-4661-923a-1a3bb4949a13" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable_0490cb78-d578-4760-bb50-6082aa814419" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_b84b18cb-6424-4098-8f84-b0593f2bf722" xlink:to="loc_us-gaap_MinorityInterestTable_0490cb78-d578-4760-bb50-6082aa814419" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_28b6f0db-3103-402b-a0c1-9b23e8637afa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_0490cb78-d578-4760-bb50-6082aa814419" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_28b6f0db-3103-402b-a0c1-9b23e8637afa" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28b6f0db-3103-402b-a0c1-9b23e8637afa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_28b6f0db-3103-402b-a0c1-9b23e8637afa" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28b6f0db-3103-402b-a0c1-9b23e8637afa_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_11dee75e-c20e-4436-9a85-1bb4c272be0c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_28b6f0db-3103-402b-a0c1-9b23e8637afa" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_11dee75e-c20e-4436-9a85-1bb4c272be0c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_FloridaTurbineTechnologiesInc.Member_f2478ea5-6b08-4f6f-b3a3-15971dd77499" xlink:href="ktos-20220626.xsd#ktos_FloridaTurbineTechnologiesInc.Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_11dee75e-c20e-4436-9a85-1bb4c272be0c" xlink:to="loc_ktos_FloridaTurbineTechnologiesInc.Member_f2478ea5-6b08-4f6f-b3a3-15971dd77499" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KTTCORELLCMember_b573d94f-81d2-4e16-b19a-648c272b2cdc" xlink:href="ktos-20220626.xsd#ktos_KTTCORELLCMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_11dee75e-c20e-4436-9a85-1bb4c272be0c" xlink:to="loc_ktos_KTTCORELLCMember_b573d94f-81d2-4e16-b19a-648c272b2cdc" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_0490cb78-d578-4760-bb50-6082aa814419" xlink:to="loc_us-gaap_StatementClassOfStockAxis_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6" xlink:to="loc_us-gaap_ClassOfStockDomain_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b0c302e8-ea20-4848-9155-ac8c6af6fb8f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_35de9f8d-dbc5-4d4b-854e-c38ff1801bc6" xlink:to="loc_us-gaap_ClassOfStockDomain_b0c302e8-ea20-4848-9155-ac8c6af6fb8f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_f86fc328-a23f-431a-a853-bdf4c7d6790b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_b0c302e8-ea20-4848-9155-ac8c6af6fb8f" xlink:to="loc_us-gaap_CommonStockMember_f86fc328-a23f-431a-a853-bdf4c7d6790b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_88189d83-bbc6-4b88-82d9-d72925a1c994" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_0490cb78-d578-4760-bb50-6082aa814419" xlink:to="loc_srt_OwnershipAxis_88189d83-bbc6-4b88-82d9-d72925a1c994" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_88189d83-bbc6-4b88-82d9-d72925a1c994_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_88189d83-bbc6-4b88-82d9-d72925a1c994" xlink:to="loc_srt_OwnershipDomain_88189d83-bbc6-4b88-82d9-d72925a1c994_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_cbd5931a-990e-4a29-94eb-e73645209e64" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_88189d83-bbc6-4b88-82d9-d72925a1c994" xlink:to="loc_srt_OwnershipDomain_cbd5931a-990e-4a29-94eb-e73645209e64" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_KTTCORELLCMember_7b235baa-9c2f-4d81-80fc-bba816fef3a2" xlink:href="ktos-20220626.xsd#ktos_KTTCORELLCMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_cbd5931a-990e-4a29-94eb-e73645209e64" xlink:to="loc_ktos_KTTCORELLCMember_7b235baa-9c2f-4d81-80fc-bba816fef3a2" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.kratosdefense.com/role/SignificantCustomersDetails" xlink:type="simple" xlink:href="ktos-20220626.xsd#SignificantCustomersDetails"/>
<link:definitionLink xlink:role="http://www.kratosdefense.com/role/SignificantCustomersDetails" xlink:type="extended" id="i497c7b7fd0974fd0996fb0868d1abd3a_SignificantCustomersDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_02cea9c1-6406-4b33-8a4e-bca4af99c7ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_f2152f93-80ad-4102-a777-0b81f8902cff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Revenues"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_02cea9c1-6406-4b33-8a4e-bca4af99c7ad" xlink:to="loc_us-gaap_Revenues_f2152f93-80ad-4102-a777-0b81f8902cff" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_134bef4f-c42f-460f-b8f8-e27400adb924" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_02cea9c1-6406-4b33-8a4e-bca4af99c7ad" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_134bef4f-c42f-460f-b8f8-e27400adb924" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a4a78d0d-3a1e-429d-a346-0047c45bd3a6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_02cea9c1-6406-4b33-8a4e-bca4af99c7ad" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a4a78d0d-3a1e-429d-a346-0047c45bd3a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_f1c7c88a-efe8-4179-9100-d634eba01ef1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a4a78d0d-3a1e-429d-a346-0047c45bd3a6" xlink:to="loc_srt_MajorCustomersAxis_f1c7c88a-efe8-4179-9100-d634eba01ef1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_f1c7c88a-efe8-4179-9100-d634eba01ef1_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_f1c7c88a-efe8-4179-9100-d634eba01ef1" xlink:to="loc_srt_NameOfMajorCustomerDomain_f1c7c88a-efe8-4179-9100-d634eba01ef1_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_77723860-24cf-4b75-8d4b-74b17f1bd38a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_f1c7c88a-efe8-4179-9100-d634eba01ef1" xlink:to="loc_srt_NameOfMajorCustomerDomain_77723860-24cf-4b75-8d4b-74b17f1bd38a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_ktos_UnitedStatesGovernmentMember_54259ba4-9067-4515-88f7-730a0b3f276f" xlink:href="ktos-20220626.xsd#ktos_UnitedStatesGovernmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_77723860-24cf-4b75-8d4b-74b17f1bd38a" xlink:to="loc_ktos_UnitedStatesGovernmentMember_54259ba4-9067-4515-88f7-730a0b3f276f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_e8bd152e-4169-4e9a-8063-eb15801dea4e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a4a78d0d-3a1e-429d-a346-0047c45bd3a6" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_e8bd152e-4169-4e9a-8063-eb15801dea4e" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_e8bd152e-4169-4e9a-8063-eb15801dea4e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_e8bd152e-4169-4e9a-8063-eb15801dea4e" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_e8bd152e-4169-4e9a-8063-eb15801dea4e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_c1b770d3-9bb6-4db5-a779-3b168448ad35" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_e8bd152e-4169-4e9a-8063-eb15801dea4e" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_c1b770d3-9bb6-4db5-a779-3b168448ad35" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GovernmentContractsConcentrationRiskMember_a586255e-54ff-49ad-99eb-07012d2b756f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GovernmentContractsConcentrationRiskMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_c1b770d3-9bb6-4db5-a779-3b168448ad35" xlink:to="loc_us-gaap_GovernmentContractsConcentrationRiskMember_a586255e-54ff-49ad-99eb-07012d2b756f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d1bdb87e-a9b0-44cf-9611-6b3938862df2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a4a78d0d-3a1e-429d-a346-0047c45bd3a6" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d1bdb87e-a9b0-44cf-9611-6b3938862df2" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d1bdb87e-a9b0-44cf-9611-6b3938862df2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d1bdb87e-a9b0-44cf-9611-6b3938862df2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d1bdb87e-a9b0-44cf-9611-6b3938862df2_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f0662846-c437-4ebe-8e03-febd22854fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d1bdb87e-a9b0-44cf-9611-6b3938862df2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f0662846-c437-4ebe-8e03-febd22854fb4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_c549fe82-2042-4be2-bd1d-c7cad142934f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SalesRevenueNetMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f0662846-c437-4ebe-8e03-febd22854fb4" xlink:to="loc_us-gaap_SalesRevenueNetMember_c549fe82-2042-4be2-bd1d-c7cad142934f" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-roles-2022.xsd#eedm"/>
<link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsAbstract"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:type="arc" order="0"/>
</link:definitionLink>
</link:linkbase>

2 Subsequent Filings that Reference this Filing

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

 2/13/24  Kratos Defense & Sec Solutio… Inc 10-K       12/31/23  118:12M
 2/23/23  Kratos Defense & Sec Solutio… Inc 10-K       12/25/22  114:13M

3 Previous Filings that this Filing References

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

 5/08/19  Kratos Defense & Sec Solutio… Inc 10-Q        3/31/19   79:43M
 5/10/18  Kratos Defense & Sec Solutio… Inc 10-Q        4/01/18   73:10M
 2/27/17  Kratos Defense & Sec Solutio… Inc 10-K       12/25/16   92:16M
↑Top
Filing Submission 0001069258-22-000054   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)
Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
About — Privacy — Redactions — Help — Sun., Apr. 28, 4:59:31.2am ET