<SEC-DOCUMENT>0000939767-19-000135.txt : 20190524
<SEC-HEADER>0000939767-19-000135.hdr.sgml : 20190524
<ACCEPTANCE-DATETIME>20190524204513
ACCESSION NUMBER:		0000939767-19-000135
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190523
FILED AS OF DATE:		20190524
DATE AS OF CHANGE:		20190524

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Garber Alan M
		CENTRAL INDEX KEY:			0001312907

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30235
		FILM NUMBER:		19855796

	MAIL ADDRESS:	
		STREET 1:		3355 MILTON COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94040

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXELIXIS, INC.
		CENTRAL INDEX KEY:			0000939767
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				043257395
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0103

	BUSINESS ADDRESS:	
		STREET 1:		1851 HARBOR BAY PARKWAY
		CITY:			ALAMEDA
		STATE:			CA
		ZIP:			94502
		BUSINESS PHONE:		6508377000

	MAIL ADDRESS:	
		STREET 1:		1851 HARBOR BAY PARKWAY
		CITY:			ALAMEDA
		STATE:			CA
		ZIP:			94502

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXELIXIS INC
		DATE OF NAME CHANGE:	20000207

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXELIXIS PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	20000106
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_155874509766298.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-05-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000939767</issuerCik>
        <issuerName>EXELIXIS, INC.</issuerName>
        <issuerTradingSymbol>EXEL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001312907</rptOwnerCik>
            <rptOwnerName>Garber Alan M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O EXELIXIS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1851 HARBOR BAY PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>ALAMEDA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94502</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.77</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-05-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>42641</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2019-05-23</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-05-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>42641.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>42641</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Option granted pursuant to the Exelixis, Inc. 2017 Equity Incentive Plan. The option is exercisable immediately, subject to repurchase provisions, and will vest as to 100% of the shares subject to the option on the first anniversary of the date of grant, subject to the Reporting Person's continuous service through such date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jennifer Drimmer Rokovich, Attorney in Fact</signatureName>
        <signatureDate>2019-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
