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<?xml version="1.0" encoding="windows-1252"?> |
<ownershipDocument> |
| <schemaVersion> X0306 </schemaVersion> |
| <documentType> 4 </documentType> |
| <periodOfReport> 2020-07-09 </periodOfReport> |
| <notSubjectToSection16> 0 </notSubjectToSection16> |
| <issuer> |
| | <issuerCik> 0001327567 </issuerCik> |
| | <issuerName> Palo Alto Networks Inc </issuerName> |
| | <issuerTradingSymbol> PANW </issuerTradingSymbol> |
| | </issuer> |
| <reportingOwner> |
| | <reportingOwnerId> |
| | | <rptOwnerCik> 0001309507 </rptOwnerCik> |
| | | <rptOwnerName> MCLAUGHLIN MARK D </rptOwnerName> |
| | | </reportingOwnerId> |
| | <reportingOwnerAddress> |
| | | <rptOwnerStreet1> C/O PALO ALTO NETWORKS INC. </rptOwnerStreet1> |
| | | <rptOwnerStreet2> 3000 TANNERY WAY </rptOwnerStreet2> |
| | | <rptOwnerCity> SANTA CLARA </rptOwnerCity> |
| | | <rptOwnerState> CA </rptOwnerState> |
| | | <rptOwnerZipCode> 95054 </rptOwnerZipCode> |
| | | <rptOwnerStateDescription></rptOwnerStateDescription> |
| | | </reportingOwnerAddress> |
| | <reportingOwnerRelationship> |
| | | <isDirector> 1 </isDirector> |
| | | <isOfficer> 0 </isOfficer> |
| | | <isTenPercentOwner> 0 </isTenPercentOwner> |
| | | <isOther> 0 </isOther> |
| | | </reportingOwnerRelationship> |
| | </reportingOwner> |
| <nonDerivativeTable> |
| | <nonDerivativeTransaction> |
| | | <securityTitle> |
| <value> Common Stock </value> |
| </securityTitle> |
| | | <transactionDate> |
| <value> 2020-07-09 </value> |
| </transactionDate> |
| | | <deemedExecutionDate></deemedExecutionDate> |
| | | <transactionCoding> |
| <transactionFormType> 4 </transactionFormType> |
| <transactionCode> S </transactionCode> |
| <equitySwapInvolved> 0 </equitySwapInvolved> |
| <footnoteId id="F1"/> |
| </transactionCoding> |
| | | <transactionTimeliness> |
| <value></value> |
| </transactionTimeliness> |
| | | <transactionAmounts> |
| <transactionShares> |
| <value> 950 </value> |
| </transactionShares> |
| <transactionPricePerShare> |
| <value> 249.00 </value> |
| </transactionPricePerShare> |
| <transactionAcquiredDisposedCode> |
| <value> D </value> |
| </transactionAcquiredDisposedCode> |
| </transactionAmounts> |
| | | <postTransactionAmounts> |
| <sharesOwnedFollowingTransaction> |
| <value> 222469 </value> |
| </sharesOwnedFollowingTransaction> |
| </postTransactionAmounts> |
| | | <ownershipNature> |
| <directOrIndirectOwnership> |
| <value> I </value> |
| </directOrIndirectOwnership> |
| <natureOfOwnership> |
| <value> See footnote </value> |
| <footnoteId id="F2"/> |
| </natureOfOwnership> |
| </ownershipNature> |
| | | </nonDerivativeTransaction> |
| | <nonDerivativeHolding> |
| | | <securityTitle> |
| <value> Common Stock </value> |
| </securityTitle> |
| | | <postTransactionAmounts> |
| <sharesOwnedFollowingTransaction> |
| <value> 97304 </value> |
| </sharesOwnedFollowingTransaction> |
| </postTransactionAmounts> |
| | | <ownershipNature> |
| <directOrIndirectOwnership> |
| <value> D </value> |
| </directOrIndirectOwnership> |
| </ownershipNature> |
| | | </nonDerivativeHolding> |
| | </nonDerivativeTable> |
| <footnotes> |
| | <footnote id="F1"> The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. </footnote> |
| | <footnote id="F2"> Shares are held by The McLaughlin Revocable Living Trust, for which the Reporting Person serves as a trustee. </footnote> |
| | </footnotes> |
| <remarks></remarks> |
| <ownerSignature> |
| | <signatureName> /s/ Jeff True, Attorney-in-Fact for Mark D. McLaughlin </signatureName> |
| | <signatureDate> 2020-07-09 </signatureDate> |
| | </ownerSignature> |
| </ownershipDocument> |