<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
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    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001231174</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>GARRETT SCOTT T</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <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>10000</noOfUnitsSold>
      <aggregateMarketValue>797238.85</aggregateMarketValue>
      <noOfUnitsOutstanding>246118192</noOfUnitsOutstanding>
      <approxSaleDate>06/15/2023</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>03/11/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2217</amountOfSecuritiesAcquired>
      <paymentDate>03/11/2021</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>03/10/2022</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1478</amountOfSecuritiesAcquired>
      <paymentDate>03/10/2022</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>03/09/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1565</amountOfSecuritiesAcquired>
      <paymentDate>03/09/2023</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/09/2020</acquiredDate>
      <natureOfAcquisitionTransaction>Stock Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>4740</amountOfSecuritiesAcquired>
      <paymentDate>11/09/2020</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>06/15/2023</noticeDate>
      <signature>/s/ Daniel Tucci, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Scott Garrett</signature>
    </noticeSignature>
  </formData>
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144
0001231174
XXXXXXXX
LIVE
0000859737
HOLOGIC INC
001-36214
250 CAMPUS DRIVE
MARLBOROUGH
MA
01752
5082632900
GARRETT SCOTT T
Director
Common
Fidelity Brokerage Services LLC
900 Salem Street
Smithfield
RI
02917
10000
797238.85
246118192
06/15/2023
NASDAQ
Common
03/11/2021
Restricted Stock Vesting
Issuer
N
2217
03/11/2021
Compensation
Common
03/10/2022
Restricted Stock Vesting
Issuer
N
1478
03/10/2022
Compensation
Common
03/09/2023
Restricted Stock Vesting
Issuer
N
1565
03/09/2023
Compensation
Common
11/09/2020
Stock Option Exercise
Issuer
N
4740
11/09/2020
Cash
Y
06/15/2023
/s/ Daniel Tucci, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Scott Garrett