<SEC-DOCUMENT>0001652956-26-000004.txt : 20260109
<SEC-HEADER>0001652956-26-000004.hdr.sgml : 20260109
<ACCEPTANCE-DATETIME>20260109160956
ACCESSION NUMBER:		0001652956-26-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260107
FILED AS OF DATE:		20260109
DATE AS OF CHANGE:		20260109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Monroe Terilyn J.
		CENTRAL INDEX KEY:			0001652956
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38683
		FILM NUMBER:		26523170

	MAIL ADDRESS:	
		STREET 1:		3100 HANOVER STREET
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Guardant Health, Inc.
		CENTRAL INDEX KEY:			0001576280
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				454139254
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3100 HANOVER STREET
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304
		BUSINESS PHONE:		855-698-8887

	MAIL ADDRESS:	
		STREET 1:		3100 HANOVER STREET
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1767992993.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-01-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001576280</issuerCik>
        <issuerName>Guardant Health, Inc.</issuerName>
        <issuerTradingSymbol>GH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001652956</rptOwnerCik>
            <rptOwnerName>Monroe Terilyn J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3100 HANOVER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief People Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-01-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6311</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>111.7521</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24710</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-01-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3632</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>112.6182</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21078</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-01-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>88</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>113.4397</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20990</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging  from $111.230 to $112.175. The Reporting Person has provided to the Issuer, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.</footnote>
        <footnote id="F2">Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging  from $112.260 to $113.250. The Reporting Person has provided to the Issuer, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.</footnote>
        <footnote id="F3">Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging  from $113.410 to $113.490. The Reporting Person has provided to the Issuer, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ John G. Saia, as attorney-in-fact for Tarilyn J. Monroe</signatureName>
        <signatureDate>2026-01-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
