<SEC-DOCUMENT>0001179110-20-008220.txt : 20200710
<SEC-HEADER>0001179110-20-008220.hdr.sgml : 20200710
<ACCEPTANCE-DATETIME>20200710182107
ACCESSION NUMBER:		0001179110-20-008220
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200708
FILED AS OF DATE:		20200710
DATE AS OF CHANGE:		20200710

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ALIABADI MANOOCHER M
		CENTRAL INDEX KEY:			0001047062

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23125
		FILM NUMBER:		201024019

	MAIL ADDRESS:	
		STREET 2:		12525 CHADRON AVE
		CITY:			HAWTHORNE
		STATE:			CA
		ZIP:			90250

	FORMER NAME:	
		FORMER CONFORMED NAME:	ALIABADI MANOOCHER
		DATE OF NAME CHANGE:	19970930

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OSI SYSTEMS INC
		CENTRAL INDEX KEY:			0001039065
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				330238801
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		12525 CHADRON AVE
		CITY:			HAWTHORNE
		STATE:			CA
		ZIP:			90250
		BUSINESS PHONE:		3109780516

	MAIL ADDRESS:	
		STREET 1:		12525 CHADRON AVENUE
		CITY:			HAWTHORNE
		STATE:			CA
		ZIP:			90250
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-07-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001039065</issuerCik>
        <issuerName>OSI SYSTEMS INC</issuerName>
        <issuerTradingSymbol>OSIS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001047062</rptOwnerCik>
            <rptOwnerName>ALIABADI MANOOCHER M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12525 CHADRON AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HAWTHORNE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90250</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Pres., Optoelectronics Div</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-07-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3942</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>79690</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares are restricted stock units issued to the Reporting Person pursuant to the OSI Systems, Inc. Amended and Restated 2012 Incentive Award Plan. Vesting and amount of shared is subject to achievement of performance targets.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Manoocher Mansouri Aliabadi</signatureName>
        <signatureDate>2020-07-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
