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

Littelfuse Inc/DE – ‘10-Q’ for 9/28/19 – ‘EX-101.DEF’

On:  Wednesday, 10/30/19, at 2:33pm ET   ·   For:  9/28/19   ·   Accession #:  889331-19-52   ·   File #:  0-20388

Previous ‘10-Q’:  ‘10-Q’ on 7/31/19 for 6/29/19   ·   Next:  ‘10-Q’ on 4/29/20 for 3/28/20   ·   Latest:  ‘10-Q’ on 11/1/23 for 9/30/23

Find Words in Filings emoji
 
  in    Show  and   Hints

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

10/30/19  Littelfuse Inc/DE                 10-Q        9/28/19   88:10M

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

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML   1.31M 
 2: EX-10.1     Material Contract                                   HTML     25K 
 3: EX-31.1     Certification -- §302 - SOA'02                      HTML     33K 
 4: EX-31.2     Certification -- §302 - SOA'02                      HTML     33K 
 5: EX-32.1     Certification -- §906 - SOA'02                      HTML     28K 
66: R1          Document and Entity Information                     HTML     80K 
11: R2          Condensed Consolidated Balance Sheets               HTML    132K 
42: R3          Condensed Consolidated Balance Sheets               HTML     38K 
                (Parentheticals)                                                 
74: R4          Condensed Consolidated Statements of Net Income     HTML     90K 
67: R5          Condensed Consolidated Statements of Comprehensive  HTML     43K 
                Income                                                           
12: R6          Condensed Consolidated Statements of Cash Flows     HTML    127K 
43: R7          Condensed Consolidated Statements of Stockholders'  HTML     94K 
                Equity                                                           
78: R8          Condensed Consolidated Statements of Stockholders'  HTML     28K 
                Equity (Parentheticals)                                          
65: R9          Summary of Significant Accounting Policies and      HTML    147K 
                Other Information                                                
82: R10         Acquisitions                                        HTML     80K 
51: R11         Inventories                                         HTML     36K 
24: R12         Property, Plant, and Equipment                      HTML     40K 
34: R13         Goodwill and Other Intangible Assets                HTML     63K 
83: R14         Lease Commitments                                   HTML     61K 
52: R15         Accrued Liabilities                                 HTML     44K 
25: R16         Restructuring, Impairment and Other Charges         HTML    109K 
35: R17         Debt                                                HTML     71K 
81: R18         Fair Value of Assets and Liabilities                HTML     83K 
53: R19         Benefit Plans                                       HTML     51K 
18: R20         Other Comprehensive Income (Loss)                   HTML    114K 
48: R21         Income Taxes                                        HTML     29K 
79: R22         Earnings Per Share                                  HTML     68K 
69: R23         Related Party Transactions                          HTML     42K 
19: R24         Segment Information                                 HTML    162K 
49: R25         Summary of Significant Accounting Policies and      HTML    150K 
                Other Information (Policies)                                     
80: R26         Summary of Significant Accounting Policies and      HTML    126K 
                Other Information (Tables)                                       
70: R27         Acquisitions (Tables)                               HTML     71K 
20: R28         Inventories (Tables)                                HTML     38K 
47: R29         Property, Plant, and Equipment (Tables)             HTML     39K 
32: R30         Goodwill and Other Intangible Assets (Tables)       HTML     67K 
23: R31         Lease Commitments (Tables)                          HTML     63K 
56: R32         Accrued Liabilities (Tables)                        HTML     43K 
85: R33         Restructuring, Impairment and Other Charges         HTML    104K 
                (Tables)                                                         
31: R34         Debt (Tables)                                       HTML     53K 
22: R35         Fair Value of Assets and Liabilities (Tables)       HTML     75K 
54: R36         Benefit Plans (Tables)                              HTML     50K 
84: R37         Other Comprehensive Income (Loss) (Tables)          HTML    118K 
33: R38         Earnings Per Share (Tables)                         HTML     63K 
21: R39         Segment Information (Tables)                        HTML    155K 
45: R40         Summary of Significant Accounting Policies and      HTML     29K 
                Other Information (Details Textual)                              
17: R41         Summary of Significant Accounting Policies and      HTML     72K 
                Other Information - Revenue Disaggregation                       
                (Details)                                                        
62: R42         Acquisitions - Narrative (Details)                  HTML     79K 
73: R43         Acquisitions - Preliminary Price Allocation         HTML     61K 
                (Details)                                                        
44: R44         Acquisitions - Business Acquisition Pro Forma       HTML     37K 
                Information (Details)                                            
16: R45         Acquisitions - Pro Forma Information Adjustments    HTML     39K 
                (Details)                                                        
61: R46         Inventories - Components of Inventories (Details)   HTML     37K 
71: R47         Property, Plant, and Equipment (Details)            HTML     46K 
46: R48         Goodwill and Other Intangible Assets - Amounts for  HTML     37K 
                Goodwill and Changes in Carrying Value by                        
                Operating Segment (Details)                                      
15: R49         Goodwill and Other Intangible Assets - Narrative    HTML     29K 
                (Details)                                                        
28: R50         Goodwill and Other Intangible Assets - Details of   HTML     40K 
                Other Intangible Assets and Related Future                       
                Amortization Expense (Details)                                   
38: R51         Goodwill and Other Intangible Assets - Estimated    HTML     41K 
                Amortization Expense Related to Intangible Assets                
                with Definite Lives (Details)                                    
86: R52         Lease Commitments - Balance Sheet, Operating Lease  HTML     41K 
                Term and Discount Rate (Details)                                 
57: R53         Lease Commitments - Lease Cost (Details)            HTML     34K 
29: R54         Lease Commitments - Maturities of Lease             HTML     42K 
                Liabilities (Details)                                            
39: R55         Lease Commitments - Supplemental Cash Flow          HTML     30K 
                Information (Details)                                            
87: R56         Accrued Liabilities (Details)                       HTML     50K 
58: R57         Restructuring, Impairment and Other Charges         HTML     63K 
                (Details)                                                        
30: R58         Debt - Carrying Amounts of Long-term Debt           HTML     57K 
                (Details)                                                        
37: R59         Debt - Narrative (Details)                          HTML    130K 
76: R60         Fair Value of Assets and Liabilities - Assets       HTML     44K 
                Measured at Fair Value (Details)                                 
63: R61         Fair Value of Assets and Liabilities - Carrying     HTML     49K 
                Value and Estimated Fair Value of Senior Notes                   
                (Details)                                                        
13: R62         Benefit Plans - Narrative (Details)                 HTML     27K 
40: R63         Benefit Plans - Benefit Plan Expenses (Details)     HTML     41K 
77: R64         Other Comprehensive Income (Loss) - Schedule of     HTML     44K 
                Components of Comprehensive Income (Loss)                        
                (Details)                                                        
64: R65         Other Comprehensive Income (Loss) - Schedule of     HTML     56K 
                Accumulated Other Comprehensive Income (Loss)                    
                (Details)                                                        
14: R66         Other Comprehensive Income (Loss) -                 HTML     32K 
                Reclassification out of Accumulated Other                        
                Comprehensive Income (Details)                                   
41: R67         Income Taxes (Details Textual)                      HTML     28K 
75: R68         Earnings Per Share - Narrative (Details)            HTML     43K 
68: R69         Earnings Per Share - Computation of Basic and       HTML     56K 
                Diluted Earnings Per Share (Details)                             
59: R70         Related Party Transactions (Details)                HTML     68K 
88: R71         Segment Information - Segment Information           HTML     65K 
                (Details)                                                        
36: R72         Segment Information - Narrative (Details)           HTML     72K 
26: R73         Segment Information - Revenues and Long-lived       HTML     51K 
                Assets by Geographical Area (Details)                            
60: XML         IDEA XML File -- Filing Summary                      XML    161K 
72: XML         XBRL Instance -- lfus201909282910-q_htm              XML   3.17M 
50: EXCEL       IDEA Workbook of Financial Reports                  XLSX     92K 
 7: EX-101.CAL  XBRL Calculations -- lfus-20190928_cal               XML    256K 
 8: EX-101.DEF  XBRL Definitions -- lfus-20190928_def                XML    535K 
 9: EX-101.LAB  XBRL Labels -- lfus-20190928_lab                     XML   1.51M 
10: EX-101.PRE  XBRL Presentations -- lfus-20190928_pre              XML    898K 
 6: EX-101.SCH  XBRL Schema -- lfus-20190928                         XSD    159K 
27: JSON        XBRL Instance as JSON Data -- MetaLinks              353±   515K 
55: ZIP         XBRL Zipped Folder -- 0000889331-19-000052-xbrl      Zip    266K 


‘EX-101.DEF’   —   XBRL Definitions — lfus-20190928_def


This Exhibit is an XBRL XML File.


                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with Wdesk from Workiva -->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<link:roleRef roleURI="http://www.littelfuse.com/role/AccruedLiabilities" xlink:href="lfus-20190928.xsd#AccruedLiabilities" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AccruedLiabilitiesDetails" xlink:href="lfus-20190928.xsd#AccruedLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AccruedLiabilitiesTables" xlink:href="lfus-20190928.xsd#AccruedLiabilitiesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/Acquisitions" xlink:href="lfus-20190928.xsd#Acquisitions" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AcquisitionsBusinessAcquisitionProFormaInformationDetails" xlink:href="lfus-20190928.xsd#AcquisitionsBusinessAcquisitionProFormaInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AcquisitionsNarrativeDetails" xlink:href="lfus-20190928.xsd#AcquisitionsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AcquisitionsPreliminaryPriceAllocationDetails" xlink:href="lfus-20190928.xsd#AcquisitionsPreliminaryPriceAllocationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AcquisitionsProFormaInformationAdjustmentsDetails" xlink:href="lfus-20190928.xsd#AcquisitionsProFormaInformationAdjustmentsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/AcquisitionsTables" xlink:href="lfus-20190928.xsd#AcquisitionsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/BenefitPlans" xlink:href="lfus-20190928.xsd#BenefitPlans" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/BenefitPlansBenefitPlanExpensesDetails" xlink:href="lfus-20190928.xsd#BenefitPlansBenefitPlanExpensesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/BenefitPlansNarrativeDetails" xlink:href="lfus-20190928.xsd#BenefitPlansNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/BenefitPlansTables" xlink:href="lfus-20190928.xsd#BenefitPlansTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedBalanceSheets" xlink:href="lfus-20190928.xsd#CondensedConsolidatedBalanceSheets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedBalanceSheetsParentheticals" xlink:href="lfus-20190928.xsd#CondensedConsolidatedBalanceSheetsParentheticals" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:href="lfus-20190928.xsd#CondensedConsolidatedStatementsOfCashFlows" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncome" xlink:href="lfus-20190928.xsd#CondensedConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfNetIncome" xlink:href="lfus-20190928.xsd#CondensedConsolidatedStatementsOfNetIncome" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfStockholdersEquity" xlink:href="lfus-20190928.xsd#CondensedConsolidatedStatementsOfStockholdersEquity" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfStockholdersEquityParentheticals" xlink:href="lfus-20190928.xsd#CondensedConsolidatedStatementsOfStockholdersEquityParentheticals" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/Debt" xlink:href="lfus-20190928.xsd#Debt" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/DebtCarryingAmountsOfLongTermDebtDetails" xlink:href="lfus-20190928.xsd#DebtCarryingAmountsOfLongTermDebtDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/DebtNarrativeDetails" xlink:href="lfus-20190928.xsd#DebtNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/DebtTables" xlink:href="lfus-20190928.xsd#DebtTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/DocumentAndEntityInformation" xlink:href="lfus-20190928.xsd#DocumentAndEntityInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/EarningsPerShare" xlink:href="lfus-20190928.xsd#EarningsPerShare" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/EarningsPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:href="lfus-20190928.xsd#EarningsPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/EarningsPerShareNarrativeDetails" xlink:href="lfus-20190928.xsd#EarningsPerShareNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/EarningsPerShareTables" xlink:href="lfus-20190928.xsd#EarningsPerShareTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilities" xlink:href="lfus-20190928.xsd#FairValueOfAssetsAndLiabilities" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesAssetsMeasuredAtFairValueDetails" xlink:href="lfus-20190928.xsd#FairValueOfAssetsAndLiabilitiesAssetsMeasuredAtFairValueDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesCarryingValueAndEstimatedFairValueOfSeniorNotesDetails" xlink:href="lfus-20190928.xsd#FairValueOfAssetsAndLiabilitiesCarryingValueAndEstimatedFairValueOfSeniorNotesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesTables" xlink:href="lfus-20190928.xsd#FairValueOfAssetsAndLiabilitiesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsAmountsForGoodwillAndChangesInCarryingValueByOperatingSegmentDetails" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssetsAmountsForGoodwillAndChangesInCarryingValueByOperatingSegmentDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsDetailsOfOtherIntangibleAssetsAndRelatedFutureAmortizationExpenseDetails" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssetsDetailsOfOtherIntangibleAssetsAndRelatedFutureAmortizationExpenseDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsEstimatedAmortizationExpenseRelatedToIntangibleAssetsWithDefiniteLivesDetails" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssetsEstimatedAmortizationExpenseRelatedToIntangibleAssetsWithDefiniteLivesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:href="lfus-20190928.xsd#GoodwillAndOtherIntangibleAssetsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/IncomeTaxes" xlink:href="lfus-20190928.xsd#IncomeTaxes" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/IncomeTaxesDetailsTextual" xlink:href="lfus-20190928.xsd#IncomeTaxesDetailsTextual" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/Inventories" xlink:href="lfus-20190928.xsd#Inventories" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/InventoriesComponentsOfInventoriesDetails" xlink:href="lfus-20190928.xsd#InventoriesComponentsOfInventoriesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/InventoriesTables" xlink:href="lfus-20190928.xsd#InventoriesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitments" xlink:href="lfus-20190928.xsd#LeaseCommitments" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitmentsBalanceSheetOperatingLeaseTermAndDiscountRateDetails" xlink:href="lfus-20190928.xsd#LeaseCommitmentsBalanceSheetOperatingLeaseTermAndDiscountRateDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitmentsLeaseCostDetails" xlink:href="lfus-20190928.xsd#LeaseCommitmentsLeaseCostDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitmentsMaturitiesOfLeaseLiabilitiesDetails" xlink:href="lfus-20190928.xsd#LeaseCommitmentsMaturitiesOfLeaseLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitmentsSupplementalCashFlowInformationDetails" xlink:href="lfus-20190928.xsd#LeaseCommitmentsSupplementalCashFlowInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/LeaseCommitmentsTables" xlink:href="lfus-20190928.xsd#LeaseCommitmentsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/OtherComprehensiveIncomeLoss" xlink:href="lfus-20190928.xsd#OtherComprehensiveIncomeLoss" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossReclassificationOutOfAccumulatedOtherComprehensiveIncomeDetails" xlink:href="lfus-20190928.xsd#OtherComprehensiveIncomeLossReclassificationOutOfAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails" xlink:href="lfus-20190928.xsd#OtherComprehensiveIncomeLossScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossScheduleOfComponentsOfComprehensiveIncomeLossDetails" xlink:href="lfus-20190928.xsd#OtherComprehensiveIncomeLossScheduleOfComponentsOfComprehensiveIncomeLossDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossTables" xlink:href="lfus-20190928.xsd#OtherComprehensiveIncomeLossTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/PropertyPlantAndEquipment" xlink:href="lfus-20190928.xsd#PropertyPlantAndEquipment" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/PropertyPlantAndEquipmentDetails" xlink:href="lfus-20190928.xsd#PropertyPlantAndEquipmentDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/PropertyPlantAndEquipmentTables" xlink:href="lfus-20190928.xsd#PropertyPlantAndEquipmentTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/RelatedPartyTransactions" xlink:href="lfus-20190928.xsd#RelatedPartyTransactions" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/RelatedPartyTransactionsDetails" xlink:href="lfus-20190928.xsd#RelatedPartyTransactionsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherCharges" xlink:href="lfus-20190928.xsd#RestructuringImpairmentAndOtherCharges" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherChargesDetails" xlink:href="lfus-20190928.xsd#RestructuringImpairmentAndOtherChargesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherChargesTables" xlink:href="lfus-20190928.xsd#RestructuringImpairmentAndOtherChargesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SegmentInformation" xlink:href="lfus-20190928.xsd#SegmentInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SegmentInformationNarrativeDetails" xlink:href="lfus-20190928.xsd#SegmentInformationNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SegmentInformationRevenuesAndLongLivedAssetsByGeographicalAreaDetails" xlink:href="lfus-20190928.xsd#SegmentInformationRevenuesAndLongLivedAssetsByGeographicalAreaDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SegmentInformationSegmentInformationDetails" xlink:href="lfus-20190928.xsd#SegmentInformationSegmentInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SegmentInformationTables" xlink:href="lfus-20190928.xsd#SegmentInformationTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformation" xlink:href="lfus-20190928.xsd#SummaryOfSignificantAccountingPoliciesAndOtherInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationDetailsTextual" xlink:href="lfus-20190928.xsd#SummaryOfSignificantAccountingPoliciesAndOtherInformationDetailsTextual" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationPolicies" xlink:href="lfus-20190928.xsd#SummaryOfSignificantAccountingPoliciesAndOtherInformationPolicies" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationRevenueDisaggregationDetails" xlink:href="lfus-20190928.xsd#SummaryOfSignificantAccountingPoliciesAndOtherInformationRevenueDisaggregationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationTables" xlink:href="lfus-20190928.xsd#SummaryOfSignificantAccountingPoliciesAndOtherInformationTables" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AccruedLiabilities" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AccruedLiabilitiesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AccruedLiabilitiesTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/Acquisitions" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AcquisitionsBusinessAcquisitionProFormaInformationDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AcquisitionsNarrativeDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_564DFAA1CACF45EDD95FFF7BC78E45CB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:to="loc_us-gaap_AwardTypeAxis_564DFAA1CACF45EDD95FFF7BC78E45CB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_73555C9AA7E17E97EA61FF7BC78E99FF_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_564DFAA1CACF45EDD95FFF7BC78E45CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_73555C9AA7E17E97EA61FF7BC78E99FF_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_73555C9AA7E17E97EA61FF7BC78E99FF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_564DFAA1CACF45EDD95FFF7BC78E45CB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_73555C9AA7E17E97EA61FF7BC78E99FF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_10EE5747ABBEDBDE2739FF7BC78E54FA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_73555C9AA7E17E97EA61FF7BC78E99FF" xlink:to="loc_us-gaap_EmployeeStockOptionMember_10EE5747ABBEDBDE2739FF7BC78E54FA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_3EC68757FF30A6A6DA91FF7BC78E1D6E" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_3EC68757FF30A6A6DA91FF7BC78E1D6E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_E51CB287EAABBBEC7E02FF7BC78EFF76_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3EC68757FF30A6A6DA91FF7BC78E1D6E" xlink:to="loc_us-gaap_SegmentDomain_E51CB287EAABBBEC7E02FF7BC78EFF76_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_E51CB287EAABBBEC7E02FF7BC78EFF76" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3EC68757FF30A6A6DA91FF7BC78E1D6E" xlink:to="loc_us-gaap_SegmentDomain_E51CB287EAABBBEC7E02FF7BC78EFF76" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="loc_us-gaap_AllOtherSegmentsMember_7BA7D6CB43878AE88AF2FF7BC78FEA4E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_E51CB287EAABBBEC7E02FF7BC78EFF76" xlink:to="loc_us-gaap_AllOtherSegmentsMember_7BA7D6CB43878AE88AF2FF7BC78FEA4E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_D7DC7007F93D4D11CEBEFF7BC78FCA95" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_D7DC7007F93D4D11CEBEFF7BC78FCA95" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_393FC09F6493E7E3B544FF7BC78F2E8B_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_D7DC7007F93D4D11CEBEFF7BC78FCA95" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_393FC09F6493E7E3B544FF7BC78F2E8B_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_393FC09F6493E7E3B544FF7BC78F2E8B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_D7DC7007F93D4D11CEBEFF7BC78FCA95" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_393FC09F6493E7E3B544FF7BC78F2E8B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IXYSCorporationMember" xlink:label="loc_lfus_IXYSCorporationMember_3EF4763C4A230B02373DFF7BC790B5BA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_393FC09F6493E7E3B544FF7BC78F2E8B" xlink:to="loc_lfus_IXYSCorporationMember_3EF4763C4A230B02373DFF7BC790B5BA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_5BEAC940813BBBC44A07FF7BC790F884" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D8259F24E4BEE16BBA45FF7BC78D825C" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_5BEAC940813BBBC44A07FF7BC790F884" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_5BEAC940813BBBC44A07FF7BC790F884" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_5BEAC940813BBBC44A07FF7BC790F884" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLossMember" xlink:label="loc_us-gaap_OperatingIncomeLossMember_7D6C2CA75798DFBA0EFFFF7BC7909F08" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C" xlink:to="loc_us-gaap_OperatingIncomeLossMember_7D6C2CA75798DFBA0EFFFF7BC7909F08" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_906869B6C0EFEDC804ADFF7BC791BE7D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_2BBADC7F0E88BEF1521DFF7BC790381C" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_906869B6C0EFEDC804ADFF7BC791BE7D" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_NumberofCustomers" xlink:label="loc_lfus_NumberofCustomers_CAE71F6FFE3910CAD388FF7BC791003C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_lfus_NumberofCustomers_CAE71F6FFE3910CAD388FF7BC791003C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_7C67F7E9DD9A097CC286FF7BC791EB42" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_7C67F7E9DD9A097CC286FF7BC791EB42" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionSharePrice" xlink:label="loc_us-gaap_BusinessAcquisitionSharePrice_05905C4CE7D627C18A1CFF7BC792F70E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessAcquisitionSharePrice_05905C4CE7D627C18A1CFF7BC792F70E" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessAcquisitionShareExchangeRatio" xlink:label="loc_lfus_BusinessAcquisitionShareExchangeRatio_06DE759BEAF284378952FF7BC7927C67" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_lfus_BusinessAcquisitionShareExchangeRatio_06DE759BEAF284378952FF7BC7927C67" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_558E630226D2FFA45C74FF7BC792206B" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_SharePrice_558E630226D2FFA45C74FF7BC792206B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationConsiderationTransferredExcludingValueOfStockOptionsConverted" xlink:label="loc_lfus_BusinessCombinationConsiderationTransferredExcludingValueOfStockOptionsConverted_E500A37600AC95F7287FFF7BC7922CC6" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_lfus_BusinessCombinationConsiderationTransferredExcludingValueOfStockOptionsConverted_E500A37600AC95F7287FFF7BC7922CC6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_D4C2374542F51F5409FBFF7BC7925DB1" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_D4C2374542F51F5409FBFF7BC7925DB1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_F596A2D1D2F578A22B29FF7BC793FF67" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_F596A2D1D2F578A22B29FF7BC793FF67" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationValueOfStockOptionsConvertedToCompanysStockOptions" xlink:label="loc_lfus_BusinessCombinationValueOfStockOptionsConvertedToCompanysStockOptions_CA115B5D993ECCB088E5FF7BC793EF0E" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_lfus_BusinessCombinationValueOfStockOptionsConvertedToCompanysStockOptions_CA115B5D993ECCB088E5FF7BC793EF0E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_6BAA25C521EE949E1FA5FF7BC793EC6C" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_6BAA25C521EE949E1FA5FF7BC793EC6C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_82AAA1B533BE4EBD8CAEFF7BC7937093" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_82AAA1B533BE4EBD8CAEFF7BC7937093" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_CDE0E586C11A26F23E80FF7BC793366E" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_CDE0E586C11A26F23E80FF7BC793366E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_02061267CC25EA8BEDF1FF7BC793D279" xlink:type="locator"/>
<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_02061267CC25EA8BEDF1FF7BC793D279" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_CC7338295A97DA96A1D9FF7BC793FCBD" xlink:type="locator"/>
<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_CC7338295A97DA96A1D9FF7BC793FCBD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_82C18D736092638AC6E2FF7BC7945607" xlink:type="locator"/>
<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_82C18D736092638AC6E2FF7BC7945607" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_D4D7090A7C97A9B62CEDFF7BC794A1EC" xlink:type="locator"/>
<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_D4D7090A7C97A9B62CEDFF7BC794A1EC" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_InventoryAmortizationPeriod" xlink:label="loc_lfus_InventoryAmortizationPeriod_7EAFC7957D3830468673FF7BC794EDDF" xlink:type="locator"/>
<link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E249E8345B2FE03630FFF7BC791235D" xlink:to="loc_lfus_InventoryAmortizationPeriod_7EAFC7957D3830468673FF7BC794EDDF" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AcquisitionsPreliminaryPriceAllocationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_E40206A51DC613FDD3BEFF4BDA378F2A" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6F6A700913A4B193D7A0FF4BDA374228" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E40206A51DC613FDD3BEFF4BDA378F2A" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6F6A700913A4B193D7A0FF4BDA374228" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_0E9229BBC3B1C7001941FF4BDA37CB01" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6F6A700913A4B193D7A0FF4BDA374228" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_0E9229BBC3B1C7001941FF4BDA37CB01" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DA3F94726AF88059AED2FF4BDA378F8F_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0E9229BBC3B1C7001941FF4BDA37CB01" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DA3F94726AF88059AED2FF4BDA378F8F_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DA3F94726AF88059AED2FF4BDA378F8F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0E9229BBC3B1C7001941FF4BDA37CB01" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DA3F94726AF88059AED2FF4BDA378F8F" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IXYSCorporationMember" xlink:label="loc_lfus_IXYSCorporationMember_53B618911FD94BC88AC5FF4BDA370B6C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DA3F94726AF88059AED2FF4BDA378F8F" xlink:to="loc_lfus_IXYSCorporationMember_53B618911FD94BC88AC5FF4BDA370B6C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E40206A51DC613FDD3BEFF4BDA378F2A" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_1B8039CA71B23E6457CEFF4BDA379E89" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_1B8039CA71B23E6457CEFF4BDA379E89" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationConsiderationTransferredCashSettledStockOptions" xlink:label="loc_lfus_BusinessCombinationConsiderationTransferredCashSettledStockOptions_A1C4A2587882DE084F7AFF4BDA37D8DB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:to="loc_lfus_BusinessCombinationConsiderationTransferredCashSettledStockOptions_A1C4A2587882DE084F7AFF4BDA37D8DB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_02F64382942981478CFFFF4BDA370C58" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_02F64382942981478CFFFF4BDA370C58" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationConsiderationTransferredConvertedStockOptions" xlink:label="loc_lfus_BusinessCombinationConsiderationTransferredConvertedStockOptions_000EE6FD9FD4B37275C2FF4BDA370701" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:to="loc_lfus_BusinessCombinationConsiderationTransferredConvertedStockOptions_000EE6FD9FD4B37275C2FF4BDA370701" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationConsiderationTransferredNetOfCashAcquired" xlink:label="loc_lfus_BusinessCombinationConsiderationTransferredNetOfCashAcquired_8C9D7C05DB1A6C1F868DFF4BDA37532D" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_EEA9C77517FB6246ADAEFF4BDA37291E" xlink:to="loc_lfus_BusinessCombinationConsiderationTransferredNetOfCashAcquired_8C9D7C05DB1A6C1F868DFF4BDA37532D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E40206A51DC613FDD3BEFF4BDA378F2A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_CDC9F1F446A7E4D6091CFF4BDA37804B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_CDC9F1F446A7E4D6091CFF4BDA37804B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_ED14694419508E826E82FF4BDA375693" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_ED14694419508E826E82FF4BDA375693" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_71AE0D2DDFB170D88783FF4BDA3709EB" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_71AE0D2DDFB170D88783FF4BDA3709EB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_9C1012438C41E2701E61FF4BDA37AB29" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_Goodwill_9C1012438C41E2701E61FF4BDA37AB29" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_A5842764EF258EBD7767FF4BDA3737BF" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_A5842764EF258EBD7767FF4BDA3737BF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_4994C82E2E5A6591EF1FFF4BDA372205" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterestAbstract_E5ECA33A9218E3295A27FF4BDA377FFF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_4994C82E2E5A6591EF1FFF4BDA372205" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_F96448FD59EF416D0F33FF4BDA37B1EC" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E40206A51DC613FDD3BEFF4BDA378F2A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_F96448FD59EF416D0F33FF4BDA37B1EC" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AcquisitionsProFormaInformationAdjustmentsDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_024338D4C84555638BBD46C8FAF3B836" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_3D9C12AE29A85CF195397DD923E85D13" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_024338D4C84555638BBD46C8FAF3B836" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_3D9C12AE29A85CF195397DD923E85D13" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="loc_us-gaap_NonrecurringAdjustmentAxis_E2CE870379905C66A938142B3350569E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_3D9C12AE29A85CF195397DD923E85D13" xlink:to="loc_us-gaap_NonrecurringAdjustmentAxis_E2CE870379905C66A938142B3350569E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_4ABCC5012CDBE38F0F9124EF26A8687A_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_E2CE870379905C66A938142B3350569E" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_4ABCC5012CDBE38F0F9124EF26A8687A_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_E2CE870379905C66A938142B3350569E" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AdjustmentToAmortizationMember" xlink:label="loc_lfus_AdjustmentToAmortizationMember_BDF9C1BD335C576BBE5949F70DCBBD6A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:to="loc_lfus_AdjustmentToAmortizationMember_BDF9C1BD335C576BBE5949F70DCBBD6A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AcquisitionRelatedCostsMember" xlink:label="loc_us-gaap_AcquisitionRelatedCostsMember_8884574D46ED598B9F2AE83802102BB2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:to="loc_us-gaap_AcquisitionRelatedCostsMember_8884574D46ED598B9F2AE83802102BB2" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AmortizationOfInventoryStepUpMember" xlink:label="loc_lfus_AmortizationOfInventoryStepUpMember_6A63891AEB4E5E3D902F8663734E4AA7" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:to="loc_lfus_AmortizationOfInventoryStepUpMember_6A63891AEB4E5E3D902F8663734E4AA7" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AdjustmentToStockCompensationMember" xlink:label="loc_lfus_AdjustmentToStockCompensationMember_68F8AD8C958A5BAFAA74280B22B2C410" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:to="loc_lfus_AdjustmentToStockCompensationMember_68F8AD8C958A5BAFAA74280B22B2C410" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AdjustmentToIncomeTaxMember" xlink:label="loc_lfus_AdjustmentToIncomeTaxMember_6EFE19DB211C56F386DD2441B1882BA4" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_9E1044F2DF6D5C19A915ECB6899F043F" xlink:to="loc_lfus_AdjustmentToIncomeTaxMember_6EFE19DB211C56F386DD2441B1882BA4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_806F96D78CB65ABBB6DAA959A90D161B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_024338D4C84555638BBD46C8FAF3B836" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_806F96D78CB65ABBB6DAA959A90D161B" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/AcquisitionsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/BenefitPlans" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/BenefitPlansBenefitPlanExpensesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/BenefitPlansNarrativeDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/BenefitPlansTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedBalanceSheetsParentheticals" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfNetIncome" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfStockholdersEquity" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_AE2D0F8638E0802B1668FF7B72B8EE79" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_68104722C35366A95CF2FF7B72B5AC8B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_AE2D0F8638E0802B1668FF7B72B8EE79" xlink:to="loc_us-gaap_StatementTable_68104722C35366A95CF2FF7B72B5AC8B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_DF38CFCB1E93C9367808FF7B72B6CB51" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_68104722C35366A95CF2FF7B72B5AC8B" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_DF38CFCB1E93C9367808FF7B72B6CB51" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_DF38CFCB1E93C9367808FF7B72B6CB51" xlink:to="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_DF38CFCB1E93C9367808FF7B72B6CB51" xlink:to="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_AD7B69C4761FB7CC2285FF7B72B7CF70" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_CommonStockMember_AD7B69C4761FB7CC2285FF7B72B7CF70" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_A78AE9178D2104394115FF7B72B76299" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_A78AE9178D2104394115FF7B72B76299" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember_7277AF0476FC78B189F7FF7B72B8FDF3" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_TreasuryStockMember_7277AF0476FC78B189F7FF7B72B8FDF3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3198D36F011DB474CAA7FF7B72B89777" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3198D36F011DB474CAA7FF7B72B89777" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_F692F2897F7C4AEED8BBFF7B72B84EE0" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_RetainedEarningsMember_F692F2897F7C4AEED8BBFF7B72B84EE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:label="loc_us-gaap_NoncontrollingInterestMember_3BE5576952EA22F752BFFF7B72B851C7" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_D5A6EC34716DEF6C1369FF7B72B6E63C" xlink:to="loc_us-gaap_NoncontrollingInterestMember_3BE5576952EA22F752BFFF7B72B851C7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_AE2D0F8638E0802B1668FF7B72B8EE79" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_9D55223C0B2D2CB029CCFF7B72B85A72" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_9D55223C0B2D2CB029CCFF7B72B85A72" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_306E6DA2976474CDD0F9FF7B72B9D58C" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_ProfitLoss_306E6DA2976474CDD0F9FF7B72B9D58C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification" xlink:label="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification_D7073A4F09BA8DEC4B27FF7B72B918A1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification_D7073A4F09BA8DEC4B27FF7B72B918A1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_12B6D226B19643B940D8FF7B72B9778E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_12B6D226B19643B940D8FF7B72B9778E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_3A206B7AA138AD9BB66BFF7B72B999FB" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_3A206B7AA138AD9BB66BFF7B72B999FB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_DB75241627EB9CD05BA4FF7B72B9B8D4" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_DB75241627EB9CD05BA4FF7B72B9B8D4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_F3F326FC6D51890F7D39FF7B72B97C37" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_F3F326FC6D51890F7D39FF7B72B97C37" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_DBCA76B4C06F04D591F9FF7B72BAFB94" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_DBCA76B4C06F04D591F9FF7B72BAFB94" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_737D10CF3353C9E6D22FFF7B72BA167C" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_737D10CF3353C9E6D22FFF7B72BA167C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_DCC9FD60638C308A1B23FF7B72BA02F1" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_DCC9FD60638C308A1B23FF7B72BA02F1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_E72B0B6FDB0ACA6DC228FF7B72BA9A93" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_D04F229D6943DF80042BFF80D5F847F2" xlink:to="loc_us-gaap_DividendsCommonStockCash_E72B0B6FDB0ACA6DC228FF7B72BA9A93" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/CondensedConsolidatedStatementsOfStockholdersEquityParentheticals" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/Debt" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/DebtCarryingAmountsOfLongTermDebtDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_D710A89D3165C52E2D53FF7BC7001DF6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_DebtInstrumentTable_D710A89D3165C52E2D53FF7BC7001DF6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_BBD097FCF28EFBFBCB01FF7BC700CFE2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_D710A89D3165C52E2D53FF7BC7001DF6" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_BBD097FCF28EFBFBCB01FF7BC700CFE2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BBD097FCF28EFBFBCB01FF7BC700CFE2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BBD097FCF28EFBFBCB01FF7BC700CFE2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnsecuredDebtMember" xlink:label="loc_us-gaap_UnsecuredDebtMember_1F506EEA7B730D9358C1FF7BC700E971" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_us-gaap_UnsecuredDebtMember_1F506EEA7B730D9358C1FF7BC700E971" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesAMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesAMember_A996ADBC4ECD1DFECC0CFF7BC701DC71" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_EuroSeniorNotesSeriesAMember_A996ADBC4ECD1DFECC0CFF7BC701DC71" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesBMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesBMember_10866B089B2060D4EEBBFF7BC701B65E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_EuroSeniorNotesSeriesBMember_10866B089B2060D4EEBBFF7BC701B65E" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesADue2022Member" xlink:label="loc_lfus_USSeniorNotesSeriesADue2022Member_C62D830A254B33B493C7FF7BC701779C" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_USSeniorNotesSeriesADue2022Member_C62D830A254B33B493C7FF7BC701779C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBDue2027Member" xlink:label="loc_lfus_USSeniorNotesSeriesBDue2027Member_8F5E575D77E8D256452FFF7BC70237D9" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_USSeniorNotesSeriesBDue2027Member_8F5E575D77E8D256452FFF7BC70237D9" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesADue2025Member" xlink:label="loc_lfus_USSeniorNotesSeriesADue2025Member_490F169814D4F70919F8FF7BC7027CD8" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_USSeniorNotesSeriesADue2025Member_490F169814D4F70919F8FF7BC7027CD8" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBDue2030Member" xlink:label="loc_lfus_USSeniorNotesSeriesBDue2030Member_A501204511765254CD46FF7BC70274A2" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_lfus_USSeniorNotesSeriesBDue2030Member_A501204511765254CD46FF7BC70274A2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NotesPayableOtherPayablesMember" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_1027B98673E0ECEA273AFF7BC7027F68" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7F25870518E5DC0B1438FF7BC700715A" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_1027B98673E0ECEA273AFF7BC7027F68" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_2E027A5FA72E1BAE5A8CFF7BC7033B82" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_2E027A5FA72E1BAE5A8CFF7BC7033B82" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_C2A038D54E96ED0A6DE2FF7BC703A949" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_C2A038D54E96ED0A6DE2FF7BC703A949" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_2A2583EBAD5E791B3E9BFF7BC703B502" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_LongTermDebt_2A2583EBAD5E791B3E9BFF7BC703B502" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_EAE1DF0B4B04F00D60B4FF7BC70358A7" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_LongTermDebtCurrent_EAE1DF0B4B04F00D60B4FF7BC70358A7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_8EEACDDB5D5A9EA8DB3DFF7BC7036CD6" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ECD5910B99536E26969FF7BC702B357" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_8EEACDDB5D5A9EA8DB3DFF7BC7036CD6" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/DebtNarrativeDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_9B683466167CEEE8EC95F465299CA184" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_9B683466167CEEE8EC95F465299CA184" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9B683466167CEEE8EC95F465299CA184" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9B683466167CEEE8EC95F465299CA184" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesAAndBMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesAAndBMember_79BACBD3DFA3EAB9DA29F465299C4CE1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_EuroSeniorNotesSeriesAAndBMember_79BACBD3DFA3EAB9DA29F465299C4CE1" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesAMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesAMember_5EC4850CF6B1F91F77BAF465299C3467" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_EuroSeniorNotesSeriesAMember_5EC4850CF6B1F91F77BAF465299C3467" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesBMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesBMember_B7F0F6E50676CC87BEF8F46529A0D1D1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_EuroSeniorNotesSeriesBMember_B7F0F6E50676CC87BEF8F46529A0D1D1" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesAAndBMember" xlink:label="loc_lfus_USSeniorNotesSeriesAAndBMember_FE431274FAD0A7252675F46529A0F0A2" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesSeriesAAndBMember_FE431274FAD0A7252675F46529A0F0A2" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesAMember" xlink:label="loc_lfus_USSeniorNotesSeriesAMember_A905CFEA4EA698A907FCF46529A0DDA6" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesSeriesAMember_A905CFEA4EA698A907FCF46529A0DDA6" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBMember" xlink:label="loc_lfus_USSeniorNotesSeriesBMember_222392DE8013C2ED879CF46529A0504B" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesSeriesBMember_222392DE8013C2ED879CF46529A0504B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesAAndBDue2025And2030Member" xlink:label="loc_lfus_USSeniorNotesAAndBDue2025And2030Member_F450B35389E2B8F3DF54F46529A06B2D" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesAAndBDue2025And2030Member_F450B35389E2B8F3DF54F46529A06B2D" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesADue2025Member" xlink:label="loc_lfus_USSeniorNotesSeriesADue2025Member_BFC995801A88732C2556F46529A03A1C" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesSeriesADue2025Member_BFC995801A88732C2556F46529A03A1C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBDue2030Member" xlink:label="loc_lfus_USSeniorNotesSeriesBDue2030Member_C1F2762F98BFED8BE5A4F46529A00002" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_DEAB932BED1255673546F465299C08D4" xlink:to="loc_lfus_USSeniorNotesSeriesBDue2030Member_C1F2762F98BFED8BE5A4F46529A00002" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_959CDFB00330453D2DC0F46529A0B682" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:to="loc_us-gaap_DebtInstrumentAxis_959CDFB00330453D2DC0F46529A0B682" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1F097AE731DB73DCFC56F46529A0B112_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_959CDFB00330453D2DC0F46529A0B682" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1F097AE731DB73DCFC56F46529A0B112_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1F097AE731DB73DCFC56F46529A0B112" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_959CDFB00330453D2DC0F46529A0B682" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1F097AE731DB73DCFC56F46529A0B112" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_CreditAgreementMember" xlink:label="loc_lfus_CreditAgreementMember_26026266376924BBC136F46529A0EF73" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1F097AE731DB73DCFC56F46529A0B112" xlink:to="loc_lfus_CreditAgreementMember_26026266376924BBC136F46529A0EF73" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_EF7AEB199D0B6476B223F46529A02100" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:to="loc_us-gaap_CreditFacilityAxis_EF7AEB199D0B6476B223F46529A02100" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_EF7AEB199D0B6476B223F46529A02100" xlink:to="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_EF7AEB199D0B6476B223F46529A02100" xlink:to="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_B96E29AA4F7EC540182DF46529A0DF89" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_B96E29AA4F7EC540182DF46529A0DF89" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_TermLoanCreditFacilityMember" xlink:label="loc_lfus_TermLoanCreditFacilityMember_7A28472BD59E053E9E94F46529A04C76" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_B4085AB05B028515CCBAF46529A04A61" xlink:to="loc_lfus_TermLoanCreditFacilityMember_7A28472BD59E053E9E94F46529A04C76" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_B01DB091EA75AF1220DDF46529A0A7BA" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:to="loc_us-gaap_VariableRateAxis_B01DB091EA75AF1220DDF46529A0A7BA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_B01DB091EA75AF1220DDF46529A0A7BA" xlink:to="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_B01DB091EA75AF1220DDF46529A0A7BA" xlink:to="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_1ABDBAE65D4DF125247BF46529A036FB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_1ABDBAE65D4DF125247BF46529A036FB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BaseRateMember" xlink:label="loc_us-gaap_BaseRateMember_20743E94BB5CBC8E7607F46529A0D904" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_E03B855266E3E31B3A58F46529A0D622" xlink:to="loc_us-gaap_BaseRateMember_20743E94BB5CBC8E7607F46529A0D904" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_72AFD69324D0AFB9B7E4F46529A059DB" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6DE8F7C4E1DA9297E150F465299C0833" xlink:to="loc_srt_RangeAxis_72AFD69324D0AFB9B7E4F46529A059DB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_72AFD69324D0AFB9B7E4F46529A059DB" xlink:to="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_72AFD69324D0AFB9B7E4F46529A059DB" xlink:to="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_E39B3FFA96C51A8AA60EF46529A481D7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75" xlink:to="loc_srt_MinimumMember_E39B3FFA96C51A8AA60EF46529A481D7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_BBEBDFC3F74179B5FCA7F46529A468E3" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3F74DF22A4CEDF3C4CEEF46529A00F75" xlink:to="loc_srt_MaximumMember_BBEBDFC3F74179B5FCA7F46529A468E3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm_737EF66A318633F8BC01F46529A4D0A2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentTerm_737EF66A318633F8BC01F46529A4D0A2" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_DebtAgreementMaximumBorrowingCapacity" xlink:label="loc_lfus_DebtAgreementMaximumBorrowingCapacity_01F7B2230AEF91BDFA4AF46529A4F754" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_DebtAgreementMaximumBorrowingCapacity_01F7B2230AEF91BDFA4AF46529A4F754" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_02A84B36810FF839A789F46529A49F81" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_02A84B36810FF839A789F46529A49F81" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacity" xlink:label="loc_lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacity_B7DE99AE7CDAE1516DEBF46529A4EB69" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacity_B7DE99AE7CDAE1516DEBF46529A4EB69" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacityMinimumIncrements" xlink:label="loc_lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacityMinimumIncrements_366630F9AA9E4D3009E0F46529A4456C" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_LineofCreditFacilityAdditionalUncommittedBorrowingCapacityMinimumIncrements_366630F9AA9E4D3009E0F46529A4456C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_NumberofAdvances" xlink:label="loc_lfus_NumberofAdvances_5B5034D64AA0F6001519F46529A4CEF5" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_NumberofAdvances_5B5034D64AA0F6001519F46529A4CEF5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_C70AC024D79F980AA2AFF46529A4D43B" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_C70AC024D79F980AA2AFF46529A4D43B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_DebtInstrumentQuarterlyPaymentsPercentageofLoan" xlink:label="loc_lfus_DebtInstrumentQuarterlyPaymentsPercentageofLoan_9521ACBFE44520EBA52DF46529A4439B" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_DebtInstrumentQuarterlyPaymentsPercentageofLoan_9521ACBFE44520EBA52DF46529A4439B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentPeriodicPayment" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPayment_04BEB2B430AD29FFE5BBF46529A41495" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPayment_04BEB2B430AD29FFE5BBF46529A41495" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_7D9CDDBFF3491E174DA4F46529A43CCF" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_7D9CDDBFF3491E174DA4F46529A43CCF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_789276DBA21155FBF69AF46529A408D4" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_789276DBA21155FBF69AF46529A408D4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_4810F034A616DA6A24AAF46529A455F4" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_4810F034A616DA6A24AAF46529A455F4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2837F126B7BB4ACD6FFEF46529A470EB" xlink:type="locator"/>
<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2837F126B7BB4ACD6FFEF46529A470EB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_B23D7F4C21D61B61A422F46529A42CBF" xlink:type="locator"/>
<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_B23D7F4C21D61B61A422F46529A42CBF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_B11C6FBA0F65E713C075F46529A43771" xlink:type="locator"/>
<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_B11C6FBA0F65E713C075F46529A43771" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_94BDFF764C2481C0F0C7F46529A4F3C2" xlink:type="locator"/>
<link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_94BDFF764C2481C0F0C7F46529A4F3C2" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_NumberofSeries" xlink:label="loc_lfus_NumberofSeries_7110B9240ECA430C7D33F46529A4C72A" xlink:type="locator"/>
<link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_lfus_NumberofSeries_7110B9240ECA430C7D33F46529A4C72A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1C93914A179BE51FA3E4F46529A43D8D" xlink:type="locator"/>
<link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1C93914A179BE51FA3E4F46529A43D8D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="loc_us-gaap_InterestExpenseDebt_FEDA56EAAB756C5FCA2BF475B543B8D4" xlink:type="locator"/>
<link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2686F6B27A41C6AD60E7F46529A40DAA" xlink:to="loc_us-gaap_InterestExpenseDebt_FEDA56EAAB756C5FCA2BF475B543B8D4" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/DebtTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/DocumentAndEntityInformation" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/EarningsPerShare" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/EarningsPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/EarningsPerShareNarrativeDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_D46B0FDC3BBCFEB7889AFFAC80386195" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_D46B0FDC3BBCFEB7889AFFAC80386195" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_C5592E3C3F6C76F78E09FFAC80393F43" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_D46B0FDC3BBCFEB7889AFFAC80386195" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_C5592E3C3F6C76F78E09FFAC80393F43" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1BFCDC7A93CB70BF9342FFAC803A3DDD_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_C5592E3C3F6C76F78E09FFAC80393F43" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1BFCDC7A93CB70BF9342FFAC803A3DDD_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1BFCDC7A93CB70BF9342FFAC803A3DDD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_C5592E3C3F6C76F78E09FFAC80393F43" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1BFCDC7A93CB70BF9342FFAC803A3DDD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_6EA12B4D994381B0F4F6FFAC803C4E7A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1BFCDC7A93CB70BF9342FFAC803A3DDD" xlink:to="loc_us-gaap_EmployeeStockOptionMember_6EA12B4D994381B0F4F6FFAC803C4E7A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareRepurchaseProgramAxis" xlink:label="loc_us-gaap_ShareRepurchaseProgramAxis_319F7E55358108D8E453FFAC803C5DBB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_D46B0FDC3BBCFEB7889AFFAC80386195" xlink:to="loc_us-gaap_ShareRepurchaseProgramAxis_319F7E55358108D8E453FFAC803C5DBB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_CA09B4D4AD84537A9DD5FFAC803C7DA1_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_319F7E55358108D8E453FFAC803C5DBB" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_CA09B4D4AD84537A9DD5FFAC803C7DA1_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_CA09B4D4AD84537A9DD5FFAC803C7DA1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_319F7E55358108D8E453FFAC803C5DBB" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_CA09B4D4AD84537A9DD5FFAC803C7DA1" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ShareRepurchaseProgramMember" xlink:label="loc_lfus_ShareRepurchaseProgramMember_516519E6BBEBA515E6BDFFAC803DEFF7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_CA09B4D4AD84537A9DD5FFAC803C7DA1" xlink:to="loc_lfus_ShareRepurchaseProgramMember_516519E6BBEBA515E6BDFFAC803DEFF7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_725C4A9D63284E9D36ACFFAC803E05FD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_725C4A9D63284E9D36ACFFAC803E05FD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased" xlink:label="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_1F2546DDEC324ED2B429FFAC803E17FF" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:to="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_1F2546DDEC324ED2B429FFAC803E17FF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_9E3204910A6B7F247FBFFFAC803F3A11" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_9E3204910A6B7F247FBFFFAC803F3A11" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_2A8D70804CA349FD668DFFAC803F9A51" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_61662E9C85728C56EFF4FFAC803D0EB4" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_2A8D70804CA349FD668DFFAC803F9A51" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/EarningsPerShareTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilities" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesAssetsMeasuredAtFairValueDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_E161FB10F60D52DFBC5A862138B83EC3" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0085F905A9E75934A78351EA64DDDC0D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_E161FB10F60D52DFBC5A862138B83EC3" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0085F905A9E75934A78351EA64DDDC0D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_D034043C1AB85922B4490CE64B22512C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0085F905A9E75934A78351EA64DDDC0D" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_D034043C1AB85922B4490CE64B22512C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_D4376D42B2C29E8B2A1826EBA708647F_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_D034043C1AB85922B4490CE64B22512C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_D4376D42B2C29E8B2A1826EBA708647F_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_E4F5034C73D15E938BE4C881E2DDC9F6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_D034043C1AB85922B4490CE64B22512C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_E4F5034C73D15E938BE4C881E2DDC9F6" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_OtherExpenseIncomeMember" xlink:label="loc_lfus_OtherExpenseIncomeMember_812676CA59FB5229B327C34CA1F310B4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_E4F5034C73D15E938BE4C881E2DDC9F6" xlink:to="loc_lfus_OtherExpenseIncomeMember_812676CA59FB5229B327C34CA1F310B4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4F39BAAC6CAB50C4BBA3F46D289C647B" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0085F905A9E75934A78351EA64DDDC0D" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4F39BAAC6CAB50C4BBA3F46D289C647B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_EF2A47467C421534A03326EBA708F3C3_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4F39BAAC6CAB50C4BBA3F46D289C647B" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_EF2A47467C421534A03326EBA708F3C3_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_FCD7E486D462578BA5401282FA9E3409" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4F39BAAC6CAB50C4BBA3F46D289C647B" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_FCD7E486D462578BA5401282FA9E3409" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_9612409B38855472843282108F1AC176" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_FCD7E486D462578BA5401282FA9E3409" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_9612409B38855472843282108F1AC176" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_6DA36F9AFB7F5C9EBC976CA0D10366C3" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_FCD7E486D462578BA5401282FA9E3409" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_6DA36F9AFB7F5C9EBC976CA0D10366C3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_CE8C7561796D5B29BD25B45D40B2705E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_FCD7E486D462578BA5401282FA9E3409" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_CE8C7561796D5B29BD25B45D40B2705E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetImpairmentCharges" xlink:label="loc_us-gaap_AssetImpairmentCharges_C89659ACB43051CEBBBB96BC722C93C9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_E161FB10F60D52DFBC5A862138B83EC3" xlink:to="loc_us-gaap_AssetImpairmentCharges_C89659ACB43051CEBBBB96BC722C93C9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquitySecuritiesFvNi" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_969A8A981B955C43B765E0417AF226E2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_E161FB10F60D52DFBC5A862138B83EC3" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_969A8A981B955C43B765E0417AF226E2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TradingSecuritiesDebt" xlink:label="loc_us-gaap_TradingSecuritiesDebt_D7D76E28896455248489515132254BF9" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_E161FB10F60D52DFBC5A862138B83EC3" xlink:to="loc_us-gaap_TradingSecuritiesDebt_D7D76E28896455248489515132254BF9" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesCarryingValueAndEstimatedFairValueOfSeniorNotesDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_F016662D84005F4D8B512373BEA1EF19" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_62BF42C844A25ADB93F8B4E123402EB0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_F016662D84005F4D8B512373BEA1EF19" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_62BF42C844A25ADB93F8B4E123402EB0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_F2750B60FC3057EC9D3BA17CDDB248B1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_62BF42C844A25ADB93F8B4E123402EB0" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_F2750B60FC3057EC9D3BA17CDDB248B1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_BD48B84D13F4DB87B81CD84A787530F8_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_F2750B60FC3057EC9D3BA17CDDB248B1" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_BD48B84D13F4DB87B81CD84A787530F8_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_C917BD66C538532AAF3EAC35A897549E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_F2750B60FC3057EC9D3BA17CDDB248B1" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_C917BD66C538532AAF3EAC35A897549E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_D9A6953688AC5C1092C779CFF0085638" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_C917BD66C538532AAF3EAC35A897549E" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_D9A6953688AC5C1092C779CFF0085638" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_9929C33F73135BC1BA5D92DB57125F62" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_D9A6953688AC5C1092C779CFF0085638" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_9929C33F73135BC1BA5D92DB57125F62" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_F0DF8D3523705C338363B8CDDB5FC6A0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_D9A6953688AC5C1092C779CFF0085638" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_F0DF8D3523705C338363B8CDDB5FC6A0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_CF2AE2FE1CFA52C2BCCCBB46EF31D377" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_62BF42C844A25ADB93F8B4E123402EB0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_CF2AE2FE1CFA52C2BCCCBB46EF31D377" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_A9915AC0615825C28283D84A7875710B_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_CF2AE2FE1CFA52C2BCCCBB46EF31D377" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_A9915AC0615825C28283D84A7875710B_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_CF2AE2FE1CFA52C2BCCCBB46EF31D377" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesAMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesAMember_C8310760011C5CAF8031C555089A9168" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_EuroSeniorNotesSeriesAMember_C8310760011C5CAF8031C555089A9168" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EuroSeniorNotesSeriesBMember" xlink:label="loc_lfus_EuroSeniorNotesSeriesBMember_43D2DD0018D858C384E1E997ACB31348" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_EuroSeniorNotesSeriesBMember_43D2DD0018D858C384E1E997ACB31348" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesADue2022Member" xlink:label="loc_lfus_USSeniorNotesSeriesADue2022Member_6DF24F41A75F555F90D1C332CB5336E6" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_USSeniorNotesSeriesADue2022Member_6DF24F41A75F555F90D1C332CB5336E6" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBDue2027Member" xlink:label="loc_lfus_USSeniorNotesSeriesBDue2027Member_9A7949E309C95BA08B78350FF262D48E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_USSeniorNotesSeriesBDue2027Member_9A7949E309C95BA08B78350FF262D48E" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesADue2025Member" xlink:label="loc_lfus_USSeniorNotesSeriesADue2025Member_0917544F81845BFBAF6E181520B46E38" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_USSeniorNotesSeriesADue2025Member_0917544F81845BFBAF6E181520B46E38" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_USSeniorNotesSeriesBDue2030Member" xlink:label="loc_lfus_USSeniorNotesSeriesBDue2030Member_87D4AF7094375F2BAD1765B604EEFA67" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_D656F2C5067A59CD8A65AAB72F63266C" xlink:to="loc_lfus_USSeniorNotesSeriesBDue2030Member_87D4AF7094375F2BAD1765B604EEFA67" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="loc_us-gaap_LongTermDebtFairValue_97C53121F1AF5DE68C9BFB2144B35A27" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_F016662D84005F4D8B512373BEA1EF19" xlink:to="loc_us-gaap_LongTermDebtFairValue_97C53121F1AF5DE68C9BFB2144B35A27" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/FairValueOfAssetsAndLiabilitiesTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssets" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsAmountsForGoodwillAndChangesInCarryingValueByOperatingSegmentDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_47135C38AAA35401B38826CCC73A76B1" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_F78FDF2F42E85ECC9D3D4EE3B425B58D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_47135C38AAA35401B38826CCC73A76B1" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_F78FDF2F42E85ECC9D3D4EE3B425B58D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_B77E8C3D842458C7BFF9A357EE3C58DC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_F78FDF2F42E85ECC9D3D4EE3B425B58D" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_B77E8C3D842458C7BFF9A357EE3C58DC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_AFE25BE5D2AEF177089ED84A779A1EAB_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_B77E8C3D842458C7BFF9A357EE3C58DC" xlink:to="loc_us-gaap_SegmentDomain_AFE25BE5D2AEF177089ED84A779A1EAB_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_5D4CAD6533CA59B1AAE715031062C54C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_B77E8C3D842458C7BFF9A357EE3C58DC" xlink:to="loc_us-gaap_SegmentDomain_5D4CAD6533CA59B1AAE715031062C54C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsMember" xlink:label="loc_lfus_ElectronicsMember_00C7234ACD1352209182A4C03A182B28" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5D4CAD6533CA59B1AAE715031062C54C" xlink:to="loc_lfus_ElectronicsMember_00C7234ACD1352209182A4C03A182B28" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AutomotiveMember" xlink:label="loc_lfus_AutomotiveMember_52C9D14177F956208106ECD919A4500C" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5D4CAD6533CA59B1AAE715031062C54C" xlink:to="loc_lfus_AutomotiveMember_52C9D14177F956208106ECD919A4500C" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IndustrialMember" xlink:label="loc_lfus_IndustrialMember_248300DA9B8358A2B0A5E755E806705B" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5D4CAD6533CA59B1AAE715031062C54C" xlink:to="loc_lfus_IndustrialMember_248300DA9B8358A2B0A5E755E806705B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_7E6E33B6E2C45D37A2BC1482F2C7AB49" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_47135C38AAA35401B38826CCC73A76B1" xlink:to="loc_us-gaap_GoodwillRollForward_7E6E33B6E2C45D37A2BC1482F2C7AB49" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_C0C41F64491F5E1991DDCC1C48925B6C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_7E6E33B6E2C45D37A2BC1482F2C7AB49" xlink:to="loc_us-gaap_Goodwill_C0C41F64491F5E1991DDCC1C48925B6C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_9E7FE1B19A985812A2B1231C93266ABC" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_7E6E33B6E2C45D37A2BC1482F2C7AB49" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_9E7FE1B19A985812A2B1231C93266ABC" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsDetailsOfOtherIntangibleAssetsAndRelatedFutureAmortizationExpenseDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_7395C7A8A2F557A1BFCA1BEDA704E196" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_AE997F7FC5AC5B128B49A89EBBEC4692" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_7395C7A8A2F557A1BFCA1BEDA704E196" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_AE997F7FC5AC5B128B49A89EBBEC4692" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_108E763930F4531FB459001B4DA362B2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_AE997F7FC5AC5B128B49A89EBBEC4692" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_108E763930F4531FB459001B4DA362B2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_13ACDE26D7E0568A9CD8F7748FA71E62_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_108E763930F4531FB459001B4DA362B2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_13ACDE26D7E0568A9CD8F7748FA71E62_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_68CAB6480B345EF0A14E0AC9DE60C815" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_108E763930F4531FB459001B4DA362B2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_68CAB6480B345EF0A14E0AC9DE60C815" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_PatentsLicensesAndSoftwareMember" xlink:label="loc_lfus_PatentsLicensesAndSoftwareMember_EF36C4073F4C5D9DBA5A4DD6BE97A36D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_68CAB6480B345EF0A14E0AC9DE60C815" xlink:to="loc_lfus_PatentsLicensesAndSoftwareMember_EF36C4073F4C5D9DBA5A4DD6BE97A36D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DistributionRightsMember" xlink:label="loc_us-gaap_DistributionRightsMember_CBA07240D7835883B6D920184D430235" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_68CAB6480B345EF0A14E0AC9DE60C815" xlink:to="loc_us-gaap_DistributionRightsMember_CBA07240D7835883B6D920184D430235" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_CustomerListsTrademarksAndTradeNamesMember" xlink:label="loc_lfus_CustomerListsTrademarksAndTradeNamesMember_D2DCB73260F95C8582F03023E350782A" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_68CAB6480B345EF0A14E0AC9DE60C815" xlink:to="loc_lfus_CustomerListsTrademarksAndTradeNamesMember_D2DCB73260F95C8582F03023E350782A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9FD13B3B34C85DD9BA6EF261B6D9C952" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_7395C7A8A2F557A1BFCA1BEDA704E196" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9FD13B3B34C85DD9BA6EF261B6D9C952" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_DB88331193F25ED28EDBD983A2D3F2AC" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_7395C7A8A2F557A1BFCA1BEDA704E196" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_DB88331193F25ED28EDBD983A2D3F2AC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_837D7B6819DA524FB4BF841D1BB49B68" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_7395C7A8A2F557A1BFCA1BEDA704E196" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_837D7B6819DA524FB4BF841D1BB49B68" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsEstimatedAmortizationExpenseRelatedToIntangibleAssetsWithDefiniteLivesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/IncomeTaxes" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/IncomeTaxesDetailsTextual" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/Inventories" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/InventoriesComponentsOfInventoriesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/InventoriesTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitments" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitmentsBalanceSheetOperatingLeaseTermAndDiscountRateDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitmentsLeaseCostDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitmentsMaturitiesOfLeaseLiabilitiesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitmentsSupplementalCashFlowInformationDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/LeaseCommitmentsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/OtherComprehensiveIncomeLoss" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossReclassificationOutOfAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_9FD345B0F0CB5BC6A05737EAC3CEBCCF" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_575A84B196B5576E9C22A8526222DB7F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_9FD345B0F0CB5BC6A05737EAC3CEBCCF" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_575A84B196B5576E9C22A8526222DB7F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3F7217CE631751738B94E54002C00988" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_575A84B196B5576E9C22A8526222DB7F" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3F7217CE631751738B94E54002C00988" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_416E387AC3AEB0262CC6D84A772D49C1_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3F7217CE631751738B94E54002C00988" xlink:to="loc_us-gaap_EquityComponentDomain_416E387AC3AEB0262CC6D84A772D49C1_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_4268513F39345EFBAD461386F6819566" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3F7217CE631751738B94E54002C00988" xlink:to="loc_us-gaap_EquityComponentDomain_4268513F39345EFBAD461386F6819566" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember_6B8ED9416E3C523F841F43A76E22129E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4268513F39345EFBAD461386F6819566" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember_6B8ED9416E3C523F841F43A76E22129E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_96B60ACB996F515DAC2DEF4579341D62" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_575A84B196B5576E9C22A8526222DB7F" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_96B60ACB996F515DAC2DEF4579341D62" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_CCE491BAA06B8AE5756ED84A772DC87E_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_96B60ACB996F515DAC2DEF4579341D62" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_CCE491BAA06B8AE5756ED84A772DC87E_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_88D608C4E947563A979CF776C292F4FF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_96B60ACB996F515DAC2DEF4579341D62" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_88D608C4E947563A979CF776C292F4FF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_A0DB3DE776025497882BB0538B728859" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_88D608C4E947563A979CF776C292F4FF" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_A0DB3DE776025497882BB0538B728859" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_67C1B4DB6B2256ECA620651E9C2FCA74" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_9FD345B0F0CB5BC6A05737EAC3CEBCCF" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_67C1B4DB6B2256ECA620651E9C2FCA74" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7835074D1754CB0BAA20FF7BC6B6A172" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A749784050B32DC2864CFF7BC6B5B772" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7835074D1754CB0BAA20FF7BC6B6A172" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A749784050B32DC2864CFF7BC6B5B772" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_CB8FCDAB853BC4274D09FF7BC6B59951" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A749784050B32DC2864CFF7BC6B5B772" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_CB8FCDAB853BC4274D09FF7BC6B59951" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_CB8FCDAB853BC4274D09FF7BC6B59951" xlink:to="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_CB8FCDAB853BC4274D09FF7BC6B59951" xlink:to="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_647DB8D352EE33E55CFAFF8B9E1B07CF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_647DB8D352EE33E55CFAFF8B9E1B07CF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_37A1FBFF79CC4B976DD0FF88DDE1B338" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_37A1FBFF79CC4B976DD0FF88DDE1B338" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_E3D2FF703C8813CC2565FF8BC3C7480E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_E3D2FF703C8813CC2565FF8BC3C7480E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_D6F5E6B24DFFAF65EF69FF8BDB7D05A7" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E5F71D1C9FDC3504B448FF7BC6B5A68D" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_D6F5E6B24DFFAF65EF69FF8BDB7D05A7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_6B73DB8930B912E86837FF7BC6B7FD07" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7835074D1754CB0BAA20FF7BC6B6A172" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_6B73DB8930B912E86837FF7BC6B7FD07" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_FA5D908D73709B5DF0B2FF7BC6B7E2B8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_6B73DB8930B912E86837FF7BC6B7FD07" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_FA5D908D73709B5DF0B2FF7BC6B7E2B8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1" xlink:label="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_6C2692506888AEDAF98FFF7BC6B793EF" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_6B73DB8930B912E86837FF7BC6B7FD07" xlink:to="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_6C2692506888AEDAF98FFF7BC6B793EF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_A716CE7550F113446C7EFF7BC6B7AE9A" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_6B73DB8930B912E86837FF7BC6B7FD07" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_A716CE7550F113446C7EFF7BC6B7AE9A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossScheduleOfComponentsOfComprehensiveIncomeLossDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3CCB21AFE0E5B363CF7EFFAC80B2460C" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_C25BB21F9E436588946CFFAC80B03335" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3CCB21AFE0E5B363CF7EFFAC80B2460C" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_C25BB21F9E436588946CFFAC80B03335" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_2B05725505EBE0F90906FFAC80B0A0FC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_C25BB21F9E436588946CFFAC80B03335" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_2B05725505EBE0F90906FFAC80B0A0FC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2B05725505EBE0F90906FFAC80B0A0FC" xlink:to="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2B05725505EBE0F90906FFAC80B0A0FC" xlink:to="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_69D6311938C56EAC3304FFBE41F709B1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_69D6311938C56EAC3304FFBE41F709B1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_E7F3BF8F5A1BCE06E288FFBE4235FD18" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2F284F5F9B9F342A9D01FFAC80B107D1" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_E7F3BF8F5A1BCE06E288FFBE4235FD18" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_CB39B94D87E3B4CDB939FFAC80B3819F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3CCB21AFE0E5B363CF7EFFAC80B2460C" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_CB39B94D87E3B4CDB939FFAC80B3819F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_CFC64FD83DBA94ED9D34FFAC80B4CC29" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3CCB21AFE0E5B363CF7EFFAC80B2460C" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_CFC64FD83DBA94ED9D34FFAC80B4CC29" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_7B83BE7C221B3936074EFFAC80B415FD" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3CCB21AFE0E5B363CF7EFFAC80B2460C" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_7B83BE7C221B3936074EFFAC80B415FD" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/OtherComprehensiveIncomeLossTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/PropertyPlantAndEquipment" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/PropertyPlantAndEquipmentDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FC143872459A15E3EEA5FFAC830B6532" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FC143872459A15E3EEA5FFAC830B6532" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_E9E31C59C79BA4DAB9F0FFAC830C1362" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FC143872459A15E3EEA5FFAC830B6532" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_E9E31C59C79BA4DAB9F0FFAC830C1362" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_E9E31C59C79BA4DAB9F0FFAC830C1362" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_E9E31C59C79BA4DAB9F0FFAC830C1362" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_E51D32F431D4CE376A04FFAC830D0CE4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20" xlink:to="loc_us-gaap_LandMember_E51D32F431D4CE376A04FFAC830D0CE4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_1ED9BC5571A6C886B589FFAC830DC056" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20" xlink:to="loc_us-gaap_BuildingMember_1ED9BC5571A6C886B589FFAC830DC056" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquipmentMember" xlink:label="loc_us-gaap_EquipmentMember_F2C98DC3B7B39DFAD6D9FFAC830DE153" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_1A17C1C32F96EECB72E7FFAC830C3A20" xlink:to="loc_us-gaap_EquipmentMember_F2C98DC3B7B39DFAD6D9FFAC830DE153" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_B64733A7BA1DAB3D9E34FFAC830E7E20" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_B64733A7BA1DAB3D9E34FFAC830E7E20" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_DFE6FB6A78F3A9DB5B48FFAC830E0B78" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_DFE6FB6A78F3A9DB5B48FFAC830E0B78" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_FC6717C2DF9DC01DF8E3FFAC830FBBC6" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_FC6717C2DF9DC01DF8E3FFAC830FBBC6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_96E3EB80F1C73FA22ADBFFAC830F146E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D0D5948E1DA59EC59D67FFAC830D4DA9" xlink:to="loc_us-gaap_Depreciation_96E3EB80F1C73FA22ADBFFAC830F146E" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/PropertyPlantAndEquipmentTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/RelatedPartyTransactions" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_B19398E0922C74EDBF6CFF4BD75F8D0D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_B19398E0922C74EDBF6CFF4BD75F8D0D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_28456255858F49EEC6F8FF4BD75F9E2A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_B19398E0922C74EDBF6CFF4BD75F8D0D" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_28456255858F49EEC6F8FF4BD75F9E2A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_28456255858F49EEC6F8FF4BD75F9E2A" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_28456255858F49EEC6F8FF4BD75F9E2A" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_PowersemMember" xlink:label="loc_lfus_PowersemMember_EF48DD23059454C998ECFF4BD76023B4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B" xlink:to="loc_lfus_PowersemMember_EF48DD23059454C998ECFF4BD76023B4" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EBTechMember" xlink:label="loc_lfus_EBTechMember_C7C20ABC76C8943306E5FF4BD760ABDF" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B" xlink:to="loc_lfus_EBTechMember_C7C20ABC76C8943306E5FF4BD760ABDF" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ATECMember" xlink:label="loc_lfus_ATECMember_2AE2E7EE3ABF9B5B3980FF4BD760BD27" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_747180B9AABA0E687BD8FF4BD760401B" xlink:to="loc_lfus_ATECMember_2AE2E7EE3ABF9B5B3980FF4BD760BD27" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_CounterpartyNameAxis" xlink:label="loc_srt_CounterpartyNameAxis_E426ABC787BD563628D5FF4BD761EC83" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_B19398E0922C74EDBF6CFF4BD75F8D0D" xlink:to="loc_srt_CounterpartyNameAxis_E426ABC787BD563628D5FF4BD761EC83" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_E426ABC787BD563628D5FF4BD761EC83" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_E426ABC787BD563628D5FF4BD761EC83" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_PowersemMember" xlink:label="loc_lfus_PowersemMember_95E8F318C7AE6D7E0287FF4BD761721B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:to="loc_lfus_PowersemMember_95E8F318C7AE6D7E0287FF4BD761721B" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_EBTechMember" xlink:label="loc_lfus_EBTechMember_E964898083A08AAD97D7FF4BD761291A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:to="loc_lfus_EBTechMember_E964898083A08AAD97D7FF4BD761291A" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ATECMember" xlink:label="loc_lfus_ATECMember_14F1D6354DC10BC77495FF4BD7613E8F" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:to="loc_lfus_ATECMember_14F1D6354DC10BC77495FF4BD7613E8F" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_MWTMember" xlink:label="loc_lfus_MWTMember_63AD61B864279BCB33FDFF4BD762A0F1" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_129540D99BF770927DC5FF4BD7617026" xlink:to="loc_lfus_MWTMember_63AD61B864279BCB33FDFF4BD762A0F1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_EDE1B493153F8B91532AFF4BD76283A3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_EDE1B493153F8B91532AFF4BD76283A3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:label="loc_us-gaap_RevenueFromRelatedParties_56BD5D555AD1F8ED853CFF4BD76254DB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_RevenueFromRelatedParties_56BD5D555AD1F8ED853CFF4BD76254DB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_D30345C787836DB8C102FF4BD762EAE1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_D30345C787836DB8C102FF4BD762EAE1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsReceivableRelatedParties" xlink:label="loc_us-gaap_AccountsReceivableRelatedParties_E2A5A7C185365C85FE9FFF4BD763B5DC" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_AccountsReceivableRelatedParties_E2A5A7C185365C85FE9FFF4BD763B5DC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent_524021D03E0351806A94FF4BD7631836" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent_524021D03E0351806A94FF4BD7631836" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_0C3828902361C64EBE16FF4BD7631996" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_0C3828902361C64EBE16FF4BD7631996" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CostMethodInvestments" xlink:label="loc_us-gaap_CostMethodInvestments_CAD68F87E44E03A2CE00FF4FC1B1578A" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_CostMethodInvestments_CAD68F87E44E03A2CE00FF4FC1B1578A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_0B0A37BEFAC1D36F17F8FF4BD763893C" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_0E3F6E796AE4DB7273ECFF4BD7626E76" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_0B0A37BEFAC1D36F17F8FF4BD763893C" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherCharges" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherChargesDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6839262D1BB40E090A7AFF7BC70F069A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6839262D1BB40E090A7AFF7BC70F069A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_6CBFE9A1B8F5F7B8588FFF7BC70F4D2F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6839262D1BB40E090A7AFF7BC70F069A" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_6CBFE9A1B8F5F7B8588FFF7BC70F4D2F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6CBFE9A1B8F5F7B8588FFF7BC70F4D2F" xlink:to="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6CBFE9A1B8F5F7B8588FFF7BC70F4D2F" xlink:to="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsMember" xlink:label="loc_lfus_ElectronicsMember_E0D7C5C46442AE166E11FF7BC7101C4E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A" xlink:to="loc_lfus_ElectronicsMember_E0D7C5C46442AE166E11FF7BC7101C4E" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AutomotiveMember" xlink:label="loc_lfus_AutomotiveMember_AC7967B42D5C672B9362FF7BC710BB8F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A" xlink:to="loc_lfus_AutomotiveMember_AC7967B42D5C672B9362FF7BC710BB8F" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IndustrialMember" xlink:label="loc_lfus_IndustrialMember_ED63730633B1DF88E0A1FF7BC7103515" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3F7FC3123CA6301A130CFF7BC70F579A" xlink:to="loc_lfus_IndustrialMember_ED63730633B1DF88E0A1FF7BC7103515" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_CB6045362DC6D2FAB135FF7BC710F17F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_6839262D1BB40E090A7AFF7BC70F069A" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_CB6045362DC6D2FAB135FF7BC710F17F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_CB6045362DC6D2FAB135FF7BC710F17F" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_CB6045362DC6D2FAB135FF7BC710F17F" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_31B0F1F9BA8B18923FA2FF7BC71153F1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E" xlink:to="loc_us-gaap_EmployeeSeveranceMember_31B0F1F9BA8B18923FA2FF7BC71153F1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherRestructuringMember" xlink:label="loc_us-gaap_OtherRestructuringMember_25CB03F44B1F2988F4DFFF7BC711916B" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_561752B820C66F5DF106FF7BC710676E" xlink:to="loc_us-gaap_OtherRestructuringMember_25CB03F44B1F2988F4DFFF7BC711916B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_6FAB997A1D201C1D384BFF7BC711429E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:to="loc_us-gaap_RestructuringCharges_6FAB997A1D201C1D384BFF7BC711429E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetImpairmentCharges" xlink:label="loc_us-gaap_OtherAssetImpairmentCharges_F198952A24AE429FE3FAFF7BC712BDFE" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:to="loc_us-gaap_OtherAssetImpairmentCharges_F198952A24AE429FE3FAFF7BC712BDFE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCostsAndAssetImpairmentCharges" xlink:label="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_65A86BD4BA499A6524D9FF7BC712C3E1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:to="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_65A86BD4BA499A6524D9FF7BC712C3E1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_DA538DB492C90C783D39FF7BC712112E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_148AB0670BA5F50FD924FF7BC711D3EE" xlink:to="loc_us-gaap_RestructuringReserve_DA538DB492C90C783D39FF7BC712112E" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/RestructuringImpairmentAndOtherChargesTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SegmentInformation" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SegmentInformationNarrativeDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_DDC06199FDE797ECA0CCFF4BD7350849" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_DDC06199FDE797ECA0CCFF4BD7350849" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67630ACE72CDB6BE6B5AFF4BD73566CD_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DDC06199FDE797ECA0CCFF4BD7350849" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67630ACE72CDB6BE6B5AFF4BD73566CD_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67630ACE72CDB6BE6B5AFF4BD73566CD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DDC06199FDE797ECA0CCFF4BD7350849" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67630ACE72CDB6BE6B5AFF4BD73566CD" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IXYSCorporationMember" xlink:label="loc_lfus_IXYSCorporationMember_574BF2AC408F947B10A6FF4BD735E3BC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67630ACE72CDB6BE6B5AFF4BD73566CD" xlink:to="loc_lfus_IXYSCorporationMember_574BF2AC408F947B10A6FF4BD735E3BC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_04695BD74F12012961BAFF4BD7354595" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_04695BD74F12012961BAFF4BD7354595" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_203ABAC7C1DF8E246D9EFF4BD736F196_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_04695BD74F12012961BAFF4BD7354595" xlink:to="loc_us-gaap_SegmentDomain_203ABAC7C1DF8E246D9EFF4BD736F196_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_203ABAC7C1DF8E246D9EFF4BD736F196" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_04695BD74F12012961BAFF4BD7354595" xlink:to="loc_us-gaap_SegmentDomain_203ABAC7C1DF8E246D9EFF4BD736F196" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="loc_us-gaap_AllOtherSegmentsMember_53E70036D1EF25414202FF4BD7364CE8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_203ABAC7C1DF8E246D9EFF4BD736F196" xlink:to="loc_us-gaap_AllOtherSegmentsMember_53E70036D1EF25414202FF4BD7364CE8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_C058E8EFC44045A53394FF4BD7369316" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_C058E8EFC44045A53394FF4BD7369316" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_4FD495D492E75E72E943FF4BD7366EFC_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_C058E8EFC44045A53394FF4BD7369316" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_4FD495D492E75E72E943FF4BD7366EFC_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_4FD495D492E75E72E943FF4BD7366EFC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_C058E8EFC44045A53394FF4BD7369316" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_4FD495D492E75E72E943FF4BD7366EFC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLossMember" xlink:label="loc_us-gaap_OperatingIncomeLossMember_EB0C397D443DBE2252A8FF4BD737AF92" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_4FD495D492E75E72E943FF4BD7366EFC" xlink:to="loc_us-gaap_OperatingIncomeLossMember_EB0C397D443DBE2252A8FF4BD737AF92" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_EE524F40E3C7327AEF78FF4BD73C3F5E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_EE524F40E3C7327AEF78FF4BD73C3F5E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_C5F516F71FF1EB77AAF0FF4BD73C8C1F_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_EE524F40E3C7327AEF78FF4BD73C3F5E" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_C5F516F71FF1EB77AAF0FF4BD73C8C1F_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_C5F516F71FF1EB77AAF0FF4BD73C8C1F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_EE524F40E3C7327AEF78FF4BD73C3F5E" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_C5F516F71FF1EB77AAF0FF4BD73C8C1F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SalesRevenueNetMember" xlink:label="loc_us-gaap_SalesRevenueNetMember_907B82DA7E0F51AF0E2EFF4BD73D593E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_C5F516F71FF1EB77AAF0FF4BD73C8C1F" xlink:to="loc_us-gaap_SalesRevenueNetMember_907B82DA7E0F51AF0E2EFF4BD73D593E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_42529858817135B33428FF4BD73D73A9" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_42529858817135B33428FF4BD73D73A9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_ADE92A2235B643401815FF4BD73DB5FA_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_42529858817135B33428FF4BD73D73A9" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_ADE92A2235B643401815FF4BD73DB5FA_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_ADE92A2235B643401815FF4BD73DB5FA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_42529858817135B33428FF4BD73D73A9" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_ADE92A2235B643401815FF4BD73DB5FA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GeographicConcentrationRiskMember" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_0A482B7366C820F5B18FFF4BD73DC056" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_ADE92A2235B643401815FF4BD73DB5FA" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_0A482B7366C820F5B18FFF4BD73DC056" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_0A38342E1EF0DC03511FFF4BD73D7BC9" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FD84FD0C3C0A9FFDF76BFF4BD7347C0E" xlink:to="loc_srt_StatementGeographicalAxis_0A38342E1EF0DC03511FFF4BD73D7BC9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_5AA11286CCEB8139CE16FF4BD73E6A2D_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_0A38342E1EF0DC03511FFF4BD73D7BC9" xlink:to="loc_srt_SegmentGeographicalDomain_5AA11286CCEB8139CE16FF4BD73E6A2D_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_5AA11286CCEB8139CE16FF4BD73E6A2D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_0A38342E1EF0DC03511FFF4BD73D7BC9" xlink:to="loc_srt_SegmentGeographicalDomain_5AA11286CCEB8139CE16FF4BD73E6A2D" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_OtherCountriesMember" xlink:label="loc_lfus_OtherCountriesMember_4FA04F8945B6337575BAFF4BD73E275A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5AA11286CCEB8139CE16FF4BD73E6A2D" xlink:to="loc_lfus_OtherCountriesMember_4FA04F8945B6337575BAFF4BD73E275A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="loc_us-gaap_NumberOfOperatingSegments_36C2CF4B017B679B88D3FF4BD73E0D51" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_NumberOfOperatingSegments_36C2CF4B017B679B88D3FF4BD73E0D51" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_BB41E3037AAF67DFF037FF4BD73F9EF0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_BB41E3037AAF67DFF037FF4BD73F9EF0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_22C3B9496616624EE01FFF4BD73FC366" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_22C3B9496616624EE01FFF4BD73FC366" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses" xlink:label="loc_lfus_BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses_09D3742DE3D3064B6967FF4BD73F6C67" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_lfus_BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses_09D3742DE3D3064B6967FF4BD73F6C67" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationBacklogAmortizationCosts" xlink:label="loc_lfus_BusinessCombinationBacklogAmortizationCosts_0FECF6ECF069F56664E0FF4BD73F44CB" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_lfus_BusinessCombinationBacklogAmortizationCosts_0FECF6ECF069F56664E0FF4BD73F44CB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_98C8B62E833274F55AE9FF4BD73FF956" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_98C8B62E833274F55AE9FF4BD73FF956" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_BusinessCombinationChangeinControlExpense" xlink:label="loc_lfus_BusinessCombinationChangeinControlExpense_6D89B50772D144482B4FFF4BD73FBEB5" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_lfus_BusinessCombinationChangeinControlExpense_6D89B50772D144482B4FFF4BD73FBEB5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_22D41E2D8636078D1505FF4BD74014FC" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_RestructuringCharges_22D41E2D8636078D1505FF4BD74014FC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetImpairmentCharges" xlink:label="loc_us-gaap_AssetImpairmentCharges_EE15665AC6FF4A17B6FBFF4BD74051CD" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_AssetImpairmentCharges_EE15665AC6FF4A17B6FBFF4BD74051CD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherRestructuringCosts" xlink:label="loc_us-gaap_OtherRestructuringCosts_90F19D772D801C98751DFF4BD740DD02" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_OtherRestructuringCosts_90F19D772D801C98751DFF4BD740DD02" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetImpairmentCharges" xlink:label="loc_us-gaap_OtherAssetImpairmentCharges_93D28328F2303404C8F6FF4BD7406934" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_OtherAssetImpairmentCharges_93D28328F2303404C8F6FF4BD7406934" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_1F9C7100962118E0C2A6FF4BD740D085" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_19F2C00F1F9869013B04FF4BD73E0538" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_1F9C7100962118E0C2A6FF4BD740D085" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SegmentInformationRevenuesAndLongLivedAssetsByGeographicalAreaDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_E00DBC29A7EBBD381CCBFF4BD727FED2" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_0CBF0A554121DF017AC5FF4BD7240A14" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E00DBC29A7EBBD381CCBFF4BD727FED2" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_0CBF0A554121DF017AC5FF4BD7240A14" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_35FD385F5153FFFCB857FF4BD725A7CF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_0CBF0A554121DF017AC5FF4BD7240A14" xlink:to="loc_srt_StatementGeographicalAxis_35FD385F5153FFFCB857FF4BD725A7CF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_35FD385F5153FFFCB857FF4BD725A7CF" xlink:to="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_35FD385F5153FFFCB857FF4BD725A7CF" xlink:to="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:type="arc"/>
<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_6159DA682D73E950F49EFF4BD725F88C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_country_US_6159DA682D73E950F49EFF4BD725F88C" xlink:type="arc"/>
<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_CN" xlink:label="loc_country_CN_19E19BB0F1F5981889AAFF4BD72602B2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_country_CN_19E19BB0F1F5981889AAFF4BD72602B2" xlink:type="arc"/>
<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_MX" xlink:label="loc_country_MX_F023C7DF5E979F2221C2FF4BD7266746" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_country_MX_F023C7DF5E979F2221C2FF4BD7266746" xlink:type="arc"/>
<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_DE" xlink:label="loc_country_DE_8D0A38F5825DCD0C4799FF4BD7265A86" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_country_DE_8D0A38F5825DCD0C4799FF4BD7265A86" xlink:type="arc"/>
<link:loc xlink:href="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_PH" xlink:label="loc_country_PH_DCA936FE3A43C5AEFBE3FF4BD726CC7E" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_country_PH_DCA936FE3A43C5AEFBE3FF4BD726CC7E" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_OtherCountriesMember" xlink:label="loc_lfus_OtherCountriesMember_7AD74AF875E8ABE1676FFF4BD7260FA2" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_081279AE44A815878DBBFF4BD725E472" xlink:to="loc_lfus_OtherCountriesMember_7AD74AF875E8ABE1676FFF4BD7260FA2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_9FAF303FA866E32DDD18FF4BD72724B9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E00DBC29A7EBBD381CCBFF4BD727FED2" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_9FAF303FA866E32DDD18FF4BD72724B9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="loc_us-gaap_NoncurrentAssets_8480C548DEAD72C1F9CDFF4BD72720BB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E00DBC29A7EBBD381CCBFF4BD727FED2" xlink:to="loc_us-gaap_NoncurrentAssets_8480C548DEAD72C1F9CDFF4BD72720BB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAdditions" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAdditions_1A1D779E3B0981C8E64AFF4BD7270B2E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E00DBC29A7EBBD381CCBFF4BD727FED2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAdditions_1A1D779E3B0981C8E64AFF4BD7270B2E" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SegmentInformationSegmentInformationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7974F875313B5F2AF192FFAC7FB6C8C3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7974F875313B5F2AF192FFAC7FB6C8C3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_8CEE11C5C09CF8DD2C66FFAD5AFA708C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7974F875313B5F2AF192FFAC7FB6C8C3" xlink:to="loc_srt_ConsolidationItemsAxis_8CEE11C5C09CF8DD2C66FFAD5AFA708C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_8CEE11C5C09CF8DD2C66FFAD5AFA708C" xlink:to="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_8CEE11C5C09CF8DD2C66FFAD5AFA708C" xlink:to="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_35E7C4109145E61EBD89FFADF1A8EA6C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF" xlink:to="loc_us-gaap_OperatingSegmentsMember_35E7C4109145E61EBD89FFADF1A8EA6C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_9B160897B123BADA1B9FFFAF229E2F4F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_77D468EF99C88C473EB5FFAD5B0CE8CF" xlink:to="loc_us-gaap_CorporateNonSegmentMember_9B160897B123BADA1B9FFFAF229E2F4F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_DA80CDE2F8E703891097FFAC7FB792EB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7974F875313B5F2AF192FFAC7FB6C8C3" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_DA80CDE2F8E703891097FFAC7FB792EB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_DA80CDE2F8E703891097FFAC7FB792EB" xlink:to="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_DA80CDE2F8E703891097FFAC7FB792EB" xlink:to="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsMember" xlink:label="loc_lfus_ElectronicsMember_B4AA12E2D3E9F9B58C4FFFAC7FB82170" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:to="loc_lfus_ElectronicsMember_B4AA12E2D3E9F9B58C4FFFAC7FB82170" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AutomotiveMember" xlink:label="loc_lfus_AutomotiveMember_EC8EC2FF32505F1C9AE7FFAC7FB8E023" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:to="loc_lfus_AutomotiveMember_EC8EC2FF32505F1C9AE7FFAC7FB8E023" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IndustrialMember" xlink:label="loc_lfus_IndustrialMember_AB16B6AE3B4340BAFE7FFFAC7FB9A2DC" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:to="loc_lfus_IndustrialMember_AB16B6AE3B4340BAFE7FFFAC7FB9A2DC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="loc_us-gaap_AllOtherSegmentsMember_7DAF13ABAAB2B40F0E9BFFAC7FB92278" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C342A4AEBE7A87412E24FFAC7FB7D318" xlink:to="loc_us-gaap_AllOtherSegmentsMember_7DAF13ABAAB2B40F0E9BFFAC7FB92278" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_EA20A97E054609369647FFAC7FB9907E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_EA20A97E054609369647FFAC7FB9907E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_36D48015661270267DD6FFAC7FBAEAA7" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_36D48015661270267DD6FFAC7FBAEAA7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_DE277052AAE87D986C38FFAC7FBBD5A9" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_OperatingIncomeLoss_DE277052AAE87D986C38FFAC7FBBD5A9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_9A953FFE9FCF359AE0B8FFAC7FBBA615" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_InterestExpense_9A953FFE9FCF359AE0B8FFAC7FBBA615" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_80B1A7712CE2A614609AFFAC7FBBFE24" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_80B1A7712CE2A614609AFFAC7FBBFE24" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_20A12FEEA1F737C3D575FFAC7FBB323B" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_20A12FEEA1F737C3D575FFAC7FBB323B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_D17A53BBE0E5B2A30027FFAC7FBB1EF2" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8A930527F87973D933AEFFAC7FB98E95" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_D17A53BBE0E5B2A30027FFAC7FBB1EF2" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SegmentInformationTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformation" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationDetailsTextual" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationPolicies" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationRevenueDisaggregationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_EAAC9055E45C5987ACEFAE718981EC27" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_92CADEE390C252539C1E27D3578812C8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_EAAC9055E45C5987ACEFAE718981EC27" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_92CADEE390C252539C1E27D3578812C8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_73AB338A4B635BB495A9D51781B45871" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_92CADEE390C252539C1E27D3578812C8" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_73AB338A4B635BB495A9D51781B45871" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9D2137EA52072197DAF9D84A7846489F_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_73AB338A4B635BB495A9D51781B45871" xlink:to="loc_us-gaap_SegmentDomain_9D2137EA52072197DAF9D84A7846489F_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3041F71F0E1A5667A011B7ACAE686140" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_73AB338A4B635BB495A9D51781B45871" xlink:to="loc_us-gaap_SegmentDomain_3041F71F0E1A5667A011B7ACAE686140" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsMember" xlink:label="loc_lfus_ElectronicsMember_DDE19799082F53E5BDFCFD70BB490929" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3041F71F0E1A5667A011B7ACAE686140" xlink:to="loc_lfus_ElectronicsMember_DDE19799082F53E5BDFCFD70BB490929" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AutomotiveMember" xlink:label="loc_lfus_AutomotiveMember_39B8BABA7B7A5170A143EF867E6E49F1" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3041F71F0E1A5667A011B7ACAE686140" xlink:to="loc_lfus_AutomotiveMember_39B8BABA7B7A5170A143EF867E6E49F1" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IndustrialMember" xlink:label="loc_lfus_IndustrialMember_7F3CF0FE87795F74A7DE46140220056B" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3041F71F0E1A5667A011B7ACAE686140" xlink:to="loc_lfus_IndustrialMember_7F3CF0FE87795F74A7DE46140220056B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_5B11E8FD8BD45AFBB4F4B711A203D8FE" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_92CADEE390C252539C1E27D3578812C8" xlink:to="loc_srt_ProductOrServiceAxis_5B11E8FD8BD45AFBB4F4B711A203D8FE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_95B1884741A41ABAB404D84A784696A3_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_5B11E8FD8BD45AFBB4F4B711A203D8FE" xlink:to="loc_srt_ProductsAndServicesDomain_95B1884741A41ABAB404D84A784696A3_9DD46B7866FC535C80DA87247C7B0DE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_5B11E8FD8BD45AFBB4F4B711A203D8FE" xlink:to="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsPassiveProductsAndSensorsMember" xlink:label="loc_lfus_ElectronicsPassiveProductsAndSensorsMember_F2A082A307D0507F81A0777CE465F9F1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_ElectronicsPassiveProductsAndSensorsMember_F2A082A307D0507F81A0777CE465F9F1" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_ElectronicsSemiconductorMember" xlink:label="loc_lfus_ElectronicsSemiconductorMember_B20DAB07A00D5DAE93109232ED7E33AA" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_ElectronicsSemiconductorMember_B20DAB07A00D5DAE93109232ED7E33AA" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_PassengerCarProductsMember" xlink:label="loc_lfus_PassengerCarProductsMember_CC061A93BECF5C919F7967665138CCF0" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_PassengerCarProductsMember_CC061A93BECF5C919F7967665138CCF0" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_AutomotiveSensorsMember" xlink:label="loc_lfus_AutomotiveSensorsMember_F3826DBC631D5E68AA28784B4DC96046" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_AutomotiveSensorsMember_F3826DBC631D5E68AA28784B4DC96046" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_CommercialVehicleProductsMember" xlink:label="loc_lfus_CommercialVehicleProductsMember_ACAEDCD2EA615B78A442774D01532F76" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_CommercialVehicleProductsMember_ACAEDCD2EA615B78A442774D01532F76" xlink:type="arc"/>
<link:loc xlink:href="lfus-20190928.xsd#lfus_IndustrialProductsMember" xlink:label="loc_lfus_IndustrialProductsMember_EDD623811ADE52A197BEE44870C588C5" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2DEE7A7DDED65C32A46FB9594F4875D2" xlink:to="loc_lfus_IndustrialProductsMember_EDD623811ADE52A197BEE44870C588C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_D2AB01DDBE0958CD88F6513D02C36074" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_EAAC9055E45C5987ACEFAE718981EC27" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_D2AB01DDBE0958CD88F6513D02C36074" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.littelfuse.com/role/SummaryOfSignificantAccountingPoliciesAndOtherInformationTables" xlink:type="extended"/>
</link:linkbase>

Top
Filing Submission 0000889331-19-000052   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
AboutPrivacyRedactionsHelp — Mon., Apr. 29, 9:38:40.1am ET