<?xml version="1.0" encoding="UTF-8"?><ns2:edgarSubmission xmlns:com="http://www.sec.gov/edgar/common" xmlns:ns2="http://www.sec.gov/edgar/ownership">
    <ns2:headerData>
        <ns2:submissionType>144</ns2:submissionType>
        <ns2:filerInfo>
            <ns2:filer>
                <ns2:filerCredentials>
                    <ns2:cik>0001239501</ns2:cik>
                    <ns2:ccc>XXXXXXXX</ns2:ccc>
                </ns2:filerCredentials>
            </ns2:filer>
            <ns2:liveTestFlag>LIVE</ns2:liveTestFlag>



        </ns2:filerInfo>
    </ns2:headerData>
    <ns2:formData>
        <ns2:issuerInfo>
            <ns2:issuerCik>0001447362</ns2:issuerCik>
            <ns2:issuerName>Castle Biosciences, Inc.</ns2:issuerName>
            <ns2:secFileNumber>001-38984</ns2:secFileNumber>
            <ns2:issuerAddress>
                <com:street1>505 S FRIENDSWOOD DR</com:street1>
                <com:street2>SUITE 401</com:street2>
                <com:city>FRIENDSWOOD</com:city>
                <com:stateOrCountry>TX</com:stateOrCountry>
                <com:zipCode>77546</com:zipCode>
            </ns2:issuerAddress>
            <ns2:issuerContactPhone>1-866-788-9007</ns2:issuerContactPhone>
            <ns2:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Derek Maetzold</ns2:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <ns2:relationshipsToIssuer>
                <ns2:relationshipToIssuer>Officer</ns2:relationshipToIssuer>
            </ns2:relationshipsToIssuer>
        </ns2:issuerInfo>
        <ns2:securitiesInformation>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:brokerOrMarketmakerDetails>
                <ns2:name>Goldman Sachs &amp; Co. LLC</ns2:name>
                <ns2:address>
                    <com:street1>200 West Street</com:street1>
                    <com:city>New York</com:city>
                    <com:stateOrCountry>NY</com:stateOrCountry>
                    <com:zipCode>10282</com:zipCode>
                </ns2:address>
            </ns2:brokerOrMarketmakerDetails>
            <ns2:noOfUnitsSold>44380</ns2:noOfUnitsSold>
            <ns2:aggregateMarketValue>1312316.6</ns2:aggregateMarketValue>
            <ns2:noOfUnitsOutstanding>27736760</ns2:noOfUnitsOutstanding>
            <ns2:approxSaleDate>08/23/2024</ns2:approxSaleDate>
            <ns2:securitiesExchangeName>NASD</ns2:securitiesExchangeName>
        </ns2:securitiesInformation>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>8494</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>8494</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>2704</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>2703</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>2703</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>2703</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>05/12/2020</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired upon option exercise</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Issuer</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>N</ns2:isGiftTransaction>
            <ns2:amountOfSecuritiesAcquired>16579</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>05/12/2020</ns2:paymentDate>
            <ns2:natureOfPayment>Option exercise</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:nothingToReportFlagOnSecuritiesSoldInPast3Months>N</ns2:nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold Descendants 2020 Trust dtd 12/4/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1212</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>28362.98</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>386</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>9033.09</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>386</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>9033.09</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>2368</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>55415.46</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1212</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>28362.98</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>386</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>9033.09</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk</ns2:name>
                <ns2:address>
                    <com:street1>505 S FRIENDSWOOD DR</com:street1>
                    <com:street2>SUITE 401</com:street2>
                    <com:city>FRIENDSWOOD</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>06/03/2024</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>386</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>9033.09</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:remarks>Total number of shares to be sold includes: 16,579 shares by Derek Maetzold, 8,494 shares by DM 2020 Irrev Tr, 8,494 shares by Maetzold Descendants 2020 Tr, 2,703 shares by Hannah Maetzold Irrev. Trust, 2,703 shares by Peter Maetzold Irrev. Trust, 2,704 shares by Emily Maetzold Irrev. Trust, 2,703 shares by John Maetzold Irrev. Trust. The sales of shares set forth herein are made in connection with a selling plan dated 12/5/2023 that is intended to comply with Rule 10b5-1(c).</ns2:remarks>
        <ns2:noticeSignature>
            <ns2:noticeDate>08/23/2024</ns2:noticeDate>
            <ns2:planAdoptionDates>
                <ns2:planAdoptionDate>12/05/2023</ns2:planAdoptionDate>
            </ns2:planAdoptionDates>
            <ns2:signature>Goldman Sachs &amp; Co. LLC on behalf of Derek Maetzold</ns2:signature>
        </ns2:noticeSignature>
    </ns2:formData>
</ns2:edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 14530}]
144
0001239501
XXXXXXXX
LIVE
0001447362
Castle Biosciences, Inc.
001-38984
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
1-866-788-9007
Derek Maetzold
Officer
Common
Goldman Sachs & Co. LLC
200 West Street
New York
NY
10282
44380
1312316.6
27736760
08/23/2024
NASD
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
8494
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
8494
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
2704
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
2703
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
2703
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
2703
10/29/2007
None
Common
05/12/2020
Acquired upon option exercise
Issuer
N
16579
05/12/2020
Option exercise
N
The Maetzold Descendants 2020 Trust dtd 12/4/2020
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
1212
28362.98
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
386
9033.09
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
386
9033.09
Derek Maetzold
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
2368
55415.46
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
1212
28362.98
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
386
9033.09
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk
505 S FRIENDSWOOD DR
SUITE 401
FRIENDSWOOD
TX
77546
Common
06/03/2024
386
9033.09
Total number of shares to be sold includes: 16,579 shares by Derek Maetzold, 8,494 shares by DM 2020 Irrev Tr, 8,494 shares by Maetzold Descendants 2020 Tr, 2,703 shares by Hannah Maetzold Irrev. Trust, 2,703 shares by Peter Maetzold Irrev. Trust, 2,704 shares by Emily Maetzold Irrev. Trust, 2,703 shares by John Maetzold Irrev. Trust. The sales of shares set forth herein are made in connection with a selling plan dated 12/5/2023 that is intended to comply with Rule 10b5-1(c).
08/23/2024
12/05/2023
Goldman Sachs & Co. LLC on behalf of Derek Maetzold