<SEC-DOCUMENT>0001179110-20-007218.txt : 20200611
<SEC-HEADER>0001179110-20-007218.hdr.sgml : 20200611
<ACCEPTANCE-DATETIME>20200611075459
ACCESSION NUMBER:		0001179110-20-007218
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200610
FILED AS OF DATE:		20200611
DATE AS OF CHANGE:		20200611

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Cavanaugh Sarah
		CENTRAL INDEX KEY:			0001709113

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15006
		FILM NUMBER:		20956211

	MAIL ADDRESS:	
		STREET 1:		C/O CELLDEX THERAPEUTICS, INC.
		STREET 2:		53 FRONTAGE ROAD, SUITE 220
		CITY:			HAMPTON
		STATE:			NJ
		ZIP:			08827

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Celldex Therapeutics, Inc.
		CENTRAL INDEX KEY:			0000744218
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				133191702
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		53 FRONTAGE ROAD
		STREET 2:		SUITE 220
		CITY:			HAMPTON
		STATE:			NJ
		ZIP:			08827
		BUSINESS PHONE:		908-200-7500

	MAIL ADDRESS:	
		STREET 1:		53 FRONTAGE ROAD
		STREET 2:		SUITE 220
		CITY:			HAMPTON
		STATE:			NJ
		ZIP:			08827

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AVANT IMMUNOTHERAPEUTICS INC
		DATE OF NAME CHANGE:	19980828

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	T CELL SCIENCES INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-06-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000744218</issuerCik>
        <issuerName>Celldex Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>CLDX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001709113</rptOwnerCik>
            <rptOwnerName>Cavanaugh Sarah</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CELLDEX THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>53 FRONTAGE ROAD, SUITE 220</rptOwnerStreet2>
            <rptOwnerCity>HAMPTON</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08827</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP of Corp Affairs &amp; Admin.</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2020-06-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1050</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1367</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Samuel B. Martin, attorney-in-fact for Sarah Cavanaugh</signatureName>
        <signatureDate>2020-06-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
