<?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>0001671755</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000016040</issuerCik>
      <issuerName>CABOT CORP</issuerName>
      <secFileNumber>001-05667</secFileNumber>
      <issuerAddress>
        <com:street1>TWO SEAPORT LANE SUITE 1400</com:street1>
        <com:city>BOSTON</com:city>
        <com:stateOrCountry>MA</com:stateOrCountry>
        <com:zipCode>02210</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>6173450100</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Kalkstein Hobart</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</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>34759</noOfUnitsSold>
      <aggregateMarketValue>4005182.32</aggregateMarketValue>
      <noOfUnitsOutstanding>54823821</noOfUnitsOutstanding>
      <approxSaleDate>11/11/2024</approxSaleDate>
      <securitiesExchangeName>NYSE</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/11/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Options Granted - 11/12/2021</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>12178</amountOfSecuritiesAcquired>
      <paymentDate>11/11/2024</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/11/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Options Granted - 11/11/2022</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>8390</amountOfSecuritiesAcquired>
      <paymentDate>11/11/2024</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/12/2013</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2042</amountOfSecuritiesAcquired>
      <paymentDate>11/12/2013</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/11/2014</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting	</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2148</amountOfSecuritiesAcquired>
      <paymentDate>11/11/2014</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/14/2017</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting	</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>373</amountOfSecuritiesAcquired>
      <paymentDate>11/14/2017</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/20/2017</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting	</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>783</amountOfSecuritiesAcquired>
      <paymentDate>11/20/2017</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>05/05/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Stock Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2825</amountOfSecuritiesAcquired>
      <paymentDate>05/05/2021</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/09/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting	</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>3391</amountOfSecuritiesAcquired>
      <paymentDate>11/09/2021</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/22/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting	</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2629</amountOfSecuritiesAcquired>
      <paymentDate>11/22/2021</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Hobart Kalkstein</name>
        <address>
          <com:street1>Two Seaport Lane</com:street1>
          <com:street2>Suite 1400</com:street2>
          <com:city>Boston</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02210-2019</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>08/19/2024</saleDate>
      <amountOfSecuritiesSold>14863</amountOfSecuritiesSold>
      <grossProceeds>1499846.14</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Hobart Kalkstein</name>
        <address>
          <com:street1>Two Seaport Lane</com:street1>
          <com:street2>Suite 1400</com:street2>
          <com:city>Boston</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02210-2019</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>08/20/2024</saleDate>
      <amountOfSecuritiesSold>5457</amountOfSecuritiesSold>
      <grossProceeds>548880.09</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>11/12/2024</noticeDate>
      <signature>/s/ Tyler Johnson, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Hobart C. Kalkstein</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
