<?xml version="1.0" encoding="UTF-8"?><own:edgarSubmission xmlns:com="http://www.sec.gov/edgar/common" xmlns:own="http://www.sec.gov/edgar/ownership">
  <!-- Generated by Workiva -->
  <own:headerData>
    <own:submissionType>144</own:submissionType>
    <own:filerInfo>
      <own:filer>
        <own:filerCredentials>
          <own:cik>0002055015</own:cik>
          <own:ccc>XXXXXXXX</own:ccc>
        </own:filerCredentials>
      </own:filer>
      <own:liveTestFlag>LIVE</own:liveTestFlag>



    </own:filerInfo>
  </own:headerData>
  <own:formData>
    <own:issuerInfo>
      <own:issuerCik>0000889331</own:issuerCik>
      <own:issuerName>LITTELFUSE INC</own:issuerName>
      <own:secFileNumber>000-20388</own:secFileNumber>
      <own:issuerAddress>
        <com:street1>6133 North River Road Ste 500</com:street1>
        <com:city>Rosemont</com:city>
        <com:stateOrCountry>IL</com:stateOrCountry>
        <com:zipCode>60018</com:zipCode>
      </own:issuerAddress>
      <own:issuerContactPhone>773-628-1000</own:issuerContactPhone>
      <own:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>David Ruppel</own:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <own:relationshipsToIssuer>
        <own:relationshipToIssuer>Officer</own:relationshipToIssuer>
      </own:relationshipsToIssuer>
    </own:issuerInfo>
    <own:securitiesInformation>
      <own:securitiesClassTitle>Common</own:securitiesClassTitle>
      <own:brokerOrMarketmakerDetails>
        <own:name>Merrill</own:name>
        <own:address>
          <com:street1>8890 Lyra Dr 5th Flr</com:street1>
          <com:city>Columbus</com:city>
          <com:stateOrCountry>OH</com:stateOrCountry>
          <com:zipCode>43240</com:zipCode>
        </own:address>
      </own:brokerOrMarketmakerDetails>
      <own:noOfUnitsSold>506</own:noOfUnitsSold>
      <own:aggregateMarketValue>225250.96</own:aggregateMarketValue>
      <own:noOfUnitsOutstanding>25288904</own:noOfUnitsOutstanding>
      <own:approxSaleDate>05/18/2026</own:approxSaleDate>
      <own:securitiesExchangeName>NASDAQ</own:securitiesExchangeName>
    </own:securitiesInformation>
    <own:securitiesToBeSold>
      <own:securitiesClassTitle>Common</own:securitiesClassTitle>
      <own:acquiredDate>04/24/2026</own:acquiredDate>
      <own:natureOfAcquisitionTransaction>Restricted Stock Vest</own:natureOfAcquisitionTransaction>
      <own:nameOfPersonfromWhomAcquired>Littelfuse, Inc</own:nameOfPersonfromWhomAcquired>
      <own:isGiftTransaction>N</own:isGiftTransaction>
      <own:amountOfSecuritiesAcquired>500</own:amountOfSecuritiesAcquired>
      <own:paymentDate>04/24/2026</own:paymentDate>
      <own:natureOfPayment>NA</own:natureOfPayment>
    </own:securitiesToBeSold>
    <own:securitiesToBeSold>
      <own:securitiesClassTitle>Common</own:securitiesClassTitle>
      <own:acquiredDate>04/24/2026</own:acquiredDate>
      <own:natureOfAcquisitionTransaction>Dividend Equivalent Stock Vest</own:natureOfAcquisitionTransaction>
      <own:nameOfPersonfromWhomAcquired>Littelfuse, Inc</own:nameOfPersonfromWhomAcquired>
      <own:isGiftTransaction>N</own:isGiftTransaction>
      <own:amountOfSecuritiesAcquired>6</own:amountOfSecuritiesAcquired>
      <own:paymentDate>04/24/2026</own:paymentDate>
      <own:natureOfPayment>NA</own:natureOfPayment>
    </own:securitiesToBeSold>
    <own:nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</own:nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <own:noticeSignature>
      <own:noticeDate>05/18/2026</own:noticeDate>
      <own:signature>David Ruppel</own:signature>
    </own:noticeSignature>
  </own:formData>
</own:edgarSubmission>
