<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2022-05-11</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000866374</issuerCik>
        <issuerName>FLEX LTD.</issuerName>
        <issuerTradingSymbol>FLEX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001929609</rptOwnerCik>
            <rptOwnerName>Tan Kwang Hooi</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FLEXTRONICS INTERNATIONAL USA, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6201 AMERICA CENTER DRIVE</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Group President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70420</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes the following: (1) 6,755 unvested restricted share units (&quot;RSUs&quot;), which will vest on May 22, 2022; (2) 4,461 unvested RSUs, which will vest on June 14, 2022; (3) 13,827 unvested RSUs, which will vest in two equal annual installments beginning on June 14, 2022; (4) 20,525 unvested RSUs, which will vest in three equal annual installments beginning on June 14, 2022; (5) 18,922 unvested RSUs, which will vest in two equal annual installments beginning on June 19, 2022; and (6) 5,930 unvested RSUs, which will vest on February 28, 2023.</footnote>
        <footnote id="F2">Each unvested RSU represents a contingent right to receive one unrestricted, fully transferable share for each vested RSU which has not been previously forfeited.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Tan Kwang Hooi, by Heather Childress as attorney-in-fact</signatureName>
        <signatureDate>2022-05-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
