<SEC-DOCUMENT>0000314808-19-000029.txt : 20190305
<SEC-HEADER>0000314808-19-000029.hdr.sgml : 20190305
<ACCEPTANCE-DATETIME>20190305174339
ACCESSION NUMBER:		0000314808-19-000029
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190303
FILED AS OF DATE:		20190305
DATE AS OF CHANGE:		20190305

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Trowell Carl
		CENTRAL INDEX KEY:			0001608903

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08097
		FILM NUMBER:		19659911

	MAIL ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J 5BQ

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Ensco plc
		CENTRAL INDEX KEY:			0000314808
		STANDARD INDUSTRIAL CLASSIFICATION:	DRILLING OIL & GAS WELLS [1381]
		IRS NUMBER:				980635229
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J5BQ
		BUSINESS PHONE:		4402076594660

	MAIL ADDRESS:	
		STREET 1:		6 CHESTERFIELD GARDENS
		CITY:			LONDON
		STATE:			X0
		ZIP:			W1J5BQ

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Ensco International plc
		DATE OF NAME CHANGE:	20091223

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ENSCO INTERNATIONAL INC
		DATE OF NAME CHANGE:	19950526

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ENERGY SERVICE COMPANY INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_155182580498870.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-03-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000314808</issuerCik>
        <issuerName>Ensco plc</issuerName>
        <issuerTradingSymbol>ESV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001608903</rptOwnerCik>
            <rptOwnerName>Trowell Carl</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6 CHESTERFIELD GARDENS</rptOwnerStreet1>
            <rptOwnerStreet2>3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>W1J 5BQ</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2019-03-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>35835</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.22</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1025831</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were withheld upon vesting to enable the reporting person to satisfy tax withholding obligations that arose upon such vesting, which will be paid by the issuer to the appropriate taxing authority in cash.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Davor S. Vukadin, by Power of Attorney</signatureName>
        <signatureDate>2019-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
