<SEC-DOCUMENT>0001764650-19-000001.txt : 20190222
<SEC-HEADER>0001764650-19-000001.hdr.sgml : 20190222
<ACCEPTANCE-DATETIME>20190222161145
ACCESSION NUMBER:		0001764650-19-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190220
FILED AS OF DATE:		20190222
DATE AS OF CHANGE:		20190222

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Romano Gianluca
		CENTRAL INDEX KEY:			0001764650

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31560
		FILM NUMBER:		19625816

	MAIL ADDRESS:	
		STREET 1:		10200 S. DE ANZA BOULEVARD
		CITY:			CUPERTINO
		STATE:			CA
		ZIP:			95014

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Seagate Technology plc
		CENTRAL INDEX KEY:			0001137789
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				980648577
		STATE OF INCORPORATION:			L2
		FISCAL YEAR END:			0628

	BUSINESS ADDRESS:	
		STREET 1:		38/39 FITZWILLIAM SQUARE
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			00000
		BUSINESS PHONE:		(353) (1) 234-3136

	MAIL ADDRESS:	
		STREET 1:		38/39 FITZWILLIAM SQUARE
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			00000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Seagate Technology
		DATE OF NAME CHANGE:	20090330

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEAGATE TECHNOLOGY
		DATE OF NAME CHANGE:	20021212

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEAGATE TECHNOLOGY HOLDINGS
		DATE OF NAME CHANGE:	20010406
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_155086988602388.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-02-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001137789</issuerCik>
        <issuerName>Seagate Technology plc</issuerName>
        <issuerTradingSymbol>STX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001764650</rptOwnerCik>
            <rptOwnerName>Romano Gianluca</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SEAGATE TECHNOLOGY PLC</rptOwnerStreet1>
            <rptOwnerStreet2>10200 S. DE ANZA BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>CUPERTINO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95014</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>NQ Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>45.89</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-02-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>115164</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2020-02-20</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-02-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>115164.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>115164</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options granted to the Reporting Person under the Seagate Technology plc 2012 Equity Incentive Plan (the &quot;Plan&quot;) are subject to a four-year vesting schedule. Subject to continuous employment, one quarter of the options will vest on February 20, 2020. The remaining options will vest in equal monthly installments over the 36 months following February 20, 2020.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Laurie Webb, Attorney-in-Fact for Gianluca Romano</signatureName>
        <signatureDate>2019-02-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
