content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001239351</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0000859737</issuerCik>
        <issuerName>HOLOGIC INC</issuerName>
        <secFileNumber>001-36214</secFileNumber>
        <issuerAddress>
          <com:street1>250 CAMPUS DRIVE</com:street1>
          <com:city>MARLBOROUGH</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>01752</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>5082632900</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MACMILLAN STEPHEN P</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
          <relationshipToIssuer>Director</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Fidelity Brokerage Services LLC</name>
          <address>
            <com:street1>900 Salem Street</com:street1>
            <com:city>Smithfield</com:city>
            <com:stateOrCountry>RI</com:stateOrCountry>
            <com:zipCode>02917</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>44039</noOfUnitsSold>
        <aggregateMarketValue>3597893.71</aggregateMarketValue>
        <noOfUnitsOutstanding>232271906</noOfUnitsOutstanding>
        <approxSaleDate>07/30/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>07/30/2024</acquiredDate>
        <natureOfAcquisitionTransaction>Options Granted - 11/07/2014</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>44039</amountOfSecuritiesAcquired>
        <paymentDate>07/30/2024</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stephen Macmillan</name>
          <address>
            <com:street1>250 Campus Drive</com:street1>
            <com:city>Marlborough</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>01752</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>07/17/2024</saleDate>
        <amountOfSecuritiesSold>3672</amountOfSecuritiesSold>
        <grossProceeds>294221.57</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>07/30/2024</noticeDate>
        <planAdoptionDates>
          <planAdoptionDate>08/30/2023</planAdoptionDate>
        </planAdoptionDates>
        <signature>/s/Wade Moss, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Stephen P. Macmillan</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
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text: 144
  0001239351
  XXXXXXXX
  LIVE
  0000859737
  HOLOGIC INC
  001-36214
  250 CAMPUS DRIVE
  MARLBOROUGH
  MA
  01752
  5082632900
  MACMILLAN STEPHEN P
  Officer
  Director
  Common
  Fidelity Brokerage Services LLC
  900 Salem Street
  Smithfield
  RI
  02917
  44039
  3597893.71
  232271906
  07/30/2024
  NASDAQ
  Common
  07/30/2024
  Options Granted - 11/07/2014
  Issuer
  N
  44039
  07/30/2024
  Cash
  N
  Stephen Macmillan
  250 Campus Drive
  Marlborough
  MA
  01752
  Common
  07/17/2024
  3672
  294221.57
  07/30/2024
  08/30/2023
  /s/Wade Moss, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Stephen P. Macmillan