<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001856542</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001447362</issuerCik>
            <issuerName>CASTLE BIOSCIENCES INC</issuerName>
            <secFileNumber>001-38984</secFileNumber>
            <issuerAddress>
                <ns2:street1>505 S. Friendswood Drive, Suite 401</ns2:street1>
                <ns2:city>Friendstown</ns2:city>
                <ns2:stateOrCountry>TX</ns2:stateOrCountry>
                <ns2:zipCode>77546</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>8667889007</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>TOBIN JUVENAL</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>12000</noOfUnitsSold>
            <aggregateMarketValue>416040.00</aggregateMarketValue>
            <noOfUnitsOutstanding>27736760</noOfUnitsOutstanding>
            <approxSaleDate>11/01/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/01/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>10000</amountOfSecuritiesAcquired>
            <paymentDate>11/01/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>01/02/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Previously Exercised Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>2000</amountOfSecuritiesAcquired>
            <paymentDate>01/02/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.&#13;
</remarks>
        <noticeSignature>
            <noticeDate>11/01/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>03/10/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Tobin Juvenal</signature>
        </noticeSignature>
    </formData>
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144
0001856542
XXXXXXXX
LIVE
0001447362
CASTLE BIOSCIENCES INC
001-38984
505 S. Friendswood Drive, Suite 401
Friendstown
TX
77546
8667889007
TOBIN JUVENAL
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
12000
416040.00
27736760
11/01/2024
NASDAQ
Common
11/01/2024
Exercise of Stock Options
Issuer
N
10000
11/01/2024
Cash
Common
01/02/2024
Previously Exercised Options
Issuer
N
2000
01/02/2024
Cash
Y
The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.
11/01/2024
03/10/2024
/s/ Tobin Juvenal