<SEC-DOCUMENT>0001580808-20-000099.txt : 20200925
<SEC-HEADER>0001580808-20-000099.hdr.sgml : 20200925
<ACCEPTANCE-DATETIME>20200925161307
ACCESSION NUMBER:		0001580808-20-000099
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200917
FILED AS OF DATE:		20200925
DATE AS OF CHANGE:		20200925

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Becker Brian
		CENTRAL INDEX KEY:			0001826095

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201200276

	MAIL ADDRESS:	
		STREET 1:		230 HOWES DRIVE
		CITY:			LOS GATOS
		STATE:			CA
		ZIP:			95032

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			A10 Networks, Inc.
		CENTRAL INDEX KEY:			0001580808
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				201446869
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2300 ORCHARD PKWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
		BUSINESS PHONE:		(408) 325-8668

	MAIL ADDRESS:	
		STREET 1:		2300 ORCHARD PKWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_160106477262176.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-09-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001580808</issuerCik>
        <issuerName>A10 Networks, Inc.</issuerName>
        <issuerTradingSymbol>ATEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001826095</rptOwnerCik>
            <rptOwnerName>Becker Brian</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2300 ORCHARD PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Interim CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34750</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Performance-based Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-07-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3250.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares represented by Restricted Stock Units (each, an &quot;RSU&quot;) that are subject to vesting, provided that the Reporting Person is a Service Provider through each vesting date. Each RSU represents a contingent right to receive one share of common stock of ATEN.</footnote>
        <footnote id="F2">Grant of 3,250 Performance-Based Restricted Stock Units, each of which represents a contingent right to receive one share of common stock of ATEN, with vesting subject to the achievement of a specified level of the volume weighted average closing price of a share of ATEN common stock during any one hundred (100) day trading period between July 20, 2020 and July 20, 2024. Vesting is subject to continued employment with the Company through the date which is thirty (30) days past the date of achievement of the performance milestone.</footnote>
        <footnote id="F3">Each share is represented by a Performance-based Restricted Stock Unit (&quot;PSU&quot;)</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert Cochran as attorney-in-fact</signatureName>
        <signatureDate>2020-09-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
