<?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>0001789632</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001786205</issuerCik>
            <issuerName>ARCELLX INC</issuerName>
            <secFileNumber>001-41259</secFileNumber>
            <issuerAddress>
                <ns2:street1>800 Bridge Parkway</ns2:street1>
                <ns2:city>Redwood City</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>94065</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>2403270603</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>CHRISTOPHER HEERY</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>70404</noOfUnitsSold>
            <aggregateMarketValue>5071904.16</aggregateMarketValue>
            <noOfUnitsOutstanding>52796618</noOfUnitsOutstanding>
            <approxSaleDate>03/22/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/22/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>49039</amountOfSecuritiesAcquired>
            <paymentDate>03/22/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>01/03/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>8921</amountOfSecuritiesAcquired>
            <paymentDate>01/03/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/07/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>12444</amountOfSecuritiesAcquired>
            <paymentDate>02/07/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>CHRISTOPHER R HEERY</name>
                <address>
                    <ns2:street1>800 Bridge Parkway</ns2:street1>
                    <ns2:city>Redwood City</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94065</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>02/08/2024</saleDate>
            <amountOfSecuritiesSold>14000</amountOfSecuritiesSold>
            <grossProceeds>861840.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>CHRISTOPHER R HEERY</name>
                <address>
                    <ns2:street1>800 Bridge Parkway</ns2:street1>
                    <ns2:city>Redwood City</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94065</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>01/04/2024</saleDate>
            <amountOfSecuritiesSold>7598</amountOfSecuritiesSold>
            <grossProceeds>419941.46</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months.
</remarks>
        <noticeSignature>
            <noticeDate>03/22/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>12/22/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Christopher Heery</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 6015}]
144
0001789632
XXXXXXXX
LIVE
0001786205
ARCELLX INC
001-41259
800 Bridge Parkway
Redwood City
CA
94065
2403270603
CHRISTOPHER HEERY
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
70404
5071904.16
52796618
03/22/2024
NASDAQ
Common
03/22/2024
Exercise of Stock Options
Issuer
N
49039
03/22/2024
Cash
Common
01/03/2024
Restricted Stock Units
Issuer
N
8921
01/03/2024
N/A
Common
02/07/2024
Restricted Stock Units
Issuer
N
12444
02/07/2024
N/A
N
CHRISTOPHER R HEERY
800 Bridge Parkway
Redwood City
CA
94065
Common
02/08/2024
14000
861840.00
CHRISTOPHER R HEERY
800 Bridge Parkway
Redwood City
CA
94065
Common
01/04/2024
7598
419941.46
The securities to be sold were and will be received upon the exercise of stock options over the next three months.
03/22/2024
12/22/2023
/s/ Christopher Heery