<SEC-DOCUMENT>0001387467-14-000136.txt : 20141113
<SEC-HEADER>0001387467-14-000136.hdr.sgml : 20141113
<ACCEPTANCE-DATETIME>20141113161315
ACCESSION NUMBER:		0001387467-14-000136
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141110
FILED AS OF DATE:		20141113
DATE AS OF CHANGE:		20141113

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALPHA & OMEGA SEMICONDUCTOR Ltd
		CENTRAL INDEX KEY:			0001387467
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		475 OAKMEAD PARKWAY
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085
		BUSINESS PHONE:		408-830-9742

	MAIL ADDRESS:	
		STREET 1:		475 OAKMEAD PARKWAY
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALPHA & OMEGA SEMICONDUCTOR LTD
		DATE OF NAME CHANGE:	20070123

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SALAMEH MICHAEL J
		CENTRAL INDEX KEY:			0001246496

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34717
		FILM NUMBER:		141218603

	MAIL ADDRESS:	
		STREET 1:		870 MAUDE AVENUE
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_141591318521259.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-11-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001387467</issuerCik>
        <issuerName>ALPHA &amp; OMEGA SEMICONDUCTOR Ltd</issuerName>
        <issuerTradingSymbol>AOSL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001246496</rptOwnerCik>
            <rptOwnerName>SALAMEH MICHAEL J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ALPHA &amp; OMEGA SEMICONDUCTOR LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>475 OAKMEAD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SUNNYVALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94085</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2014-11-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4488</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11283</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the Issuer's common shares underlying restricted stock units (RSUs) awarded to the Reporting Person for service on the board of directors pursuant to the Issuer automatic grant program for non-employee directors. The RSUs will vest in four (4) successive equal quarterly installments upon the Reporting Person's completion of three months of Board service over the one-year period measured from the grant date.</footnote>
        <footnote id="F2">Includes 2,000 common shares issued upon vesting of shares subject to RSUs granted on March 24, 2014.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Yanbing Hong, attorney-in-fact for Michael J. Salameh</signatureName>
        <signatureDate>2014-11-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
