| 22 Nov 12 | D. Potts Daniel Potts |  West Ham UnitedWHU | → |  Colchester UnitedCOL | Loan |
| 22 Nov 12 | P. McCallum Paul McCallum | West Ham UnitedWHU | → |  AFC WimbledonWIM | Loan |
| 22 Nov 12 | R. Hall Robert Hall | West Ham UnitedWHU | → |  Birmingham CityBIR | Loan |
| 22 Nov 12 | B. Turgott Blair Turgott | West Ham UnitedWHU | → |  Bradford CityBRD | Loan |
| 22 Nov 12 | R. Hall Robert Hall | West Ham UnitedWHU | → | Birmingham CityBIR | Loan |
| 16 Oct 12 | S. Henderson Stephen Henderson | West Ham UnitedWHU | → |  Ipswich TownIPS | Loan |
| 16 Oct 12 | S. Henderson Stephen Henderson | West Ham UnitedWHU | → | Ipswich TownIPS | Loan |
| 31 Aug 12 | N. Maynard Nicky Maynard | West Ham UnitedWHU | → |  Cardiff CityCAR | Undisclosed |
| 31 Aug 12 | N. Maynard Nicky Maynard | West Ham UnitedWHU | → | Cardiff CityCAR | Undisclosed |
| 31 Aug 12 | Y. Benayoun Yossi Benayoun |  ChelseaCHE | → | West Ham UnitedWHU | Loan |
| 30 Aug 12 | A. Carroll Andy Carroll |  LiverpoolLIV | → | West Ham UnitedWHU | Loan |
| 24 Aug 12 | M. Jarvis Matthew Jarvis |  Wolverhampton WanderersWOL | → | West Ham UnitedWHU | Undisclosed |
| 24 Aug 12 | M. Jarvis Matthew Jarvis | Wolverhampton WanderersWOL | → | West Ham UnitedWHU | Undisclosed |
| 21 Aug 12 | S. Baldock Sam Baldock | West Ham UnitedWHU | → |  Bristol CityBRC | Undisclosed |
| 21 Aug 12 | S. Baldock Sam Baldock | West Ham UnitedWHU | → | Bristol CityBRC | Undisclosed |
| 17 Aug 12 | C. Montano Cristian Montano | West Ham UnitedWHU | → |  Oldham AthleticOLD | Undisclosed |
| 10 Aug 12 | A. Diarra Alou Diarra |  MarseilleMAR | → | West Ham UnitedWHU | Undisclosed |
| 10 Aug 12 | A. Diarra Alou Diarra | MarseilleMAR | → | West Ham UnitedWHU | Undisclosed |
| 06 Aug 12 | R. Morrison Ravel Morrison | West Ham UnitedWHU | → | Birmingham CityBIR | Loan |
| 06 Aug 12 | R. Morrison Ravel Morrison | West Ham UnitedWHU | → | Birmingham CityBIR | Loan |
| 01 Aug 12 | J. Collins James Collins |  Aston VillaAVL | → | West Ham UnitedWHU | Undisclosed |
| 23 Jul 12 | Raphael Spiegel |  GrasshoppersGCZ | → | West Ham UnitedWHU | Undisclosed |
| 20 Jul 12 | A. Faye Abdoulaye Faye | West Ham UnitedWHU | → |  Hull CityHUL | Free |
| 20 Jul 12 | A. Faye Abdoulaye Faye | West Ham UnitedWHU | → | Hull CityHUL | Free |
| 18 Jul 12 | M. Maïga Modibo Maïga |  SochauxSOC | → | West Ham UnitedWHU | Undisclosed |
| 18 Jul 12 | M. Maïga Modibo Maïga | SochauxSOC | → | West Ham UnitedWHU | Undisclosed |
| 05 Jul 12 | M. Stech Marek Stech | West Ham UnitedWHU | → |  Yeovil TownYEO | Free |
| 04 Jul 12 | F. Sears Freddie Sears | West Ham UnitedWHU | → | Colchester UnitedCOL | Free |
| 03 Jul 12 | P. Barrera Pablo Barrera | West Ham UnitedWHU | → |  Cruz AzulCAZ | Undisclosed |
| 03 Jul 12 | P. Barrera Pablo Barrera | West Ham UnitedWHU | → | Cruz AzulCAZ | Undisclosed |
| 03 Jul 12 | O. Lee Oliver Lee | West Ham UnitedWHU | → |  BarnetBAR | Free |
| 01 Jul 12 | J. Jaaskelainen Jussi Jaaskelainen |  Bolton WanderersBOL | → | West Ham UnitedWHU | Free |
| 01 Jul 12 | G. McCartney George McCartney |  SunderlandSUN | → | West Ham UnitedWHU | Undisclosed |
| 01 Jul 12 | M. Diamé Mohamed Diamé |  Wigan AthleticWGA | → | West Ham UnitedWHU | Free |
| 01 Jul 12 | R. Green Robert Green | West Ham UnitedWHU | → |  Queens Park RangersQPR | Free |
| 01 Jul 12 | J. Jaaskelainen Jussi Jaaskelainen | Bolton WanderersBOL | → | West Ham UnitedWHU | Free |
| 27 Jun 12 | J. Brown Jordon Brown | West Ham UnitedWHU | → | BarnetBAR | Free |
| 22 Jun 12 | F. Nouble Frank Nouble | West Ham UnitedWHU | → | Wolverhampton WanderersWOL | Free |
| 22 Jun 12 | F. Nouble Frank Nouble | West Ham UnitedWHU | → | Wolverhampton WanderersWOL | Free |
| 14 Jun 12 | S. Cowler Sam Cowler | West Ham UnitedWHU | → | BarnetBAR | Free |
| 21 May 12 | S. Henderson Stephen Henderson |  PortsmouthPOR | → | West Ham UnitedWHU | Undisclosed |
| 16 Mar 12 | R. Hall Robert Hall | West Ham UnitedWHU | → |  Milton Keynes DonsMKD | Loan |
| 16 Mar 12 | C. Montano Cristian Montano | West Ham UnitedWHU | → |  Oxford UnitedOXF | Loan |
| 16 Mar 12 | S. Henderson Stephen Henderson | PortsmouthPOR | → | West Ham UnitedWHU | Loan |
| 09 Mar 12 | D. Collins Danny Collins |  Stoke CitySTK | → | West Ham UnitedWHU | Loan |
| 09 Mar 12 | D. Collins Danny Collins | Stoke CitySTK | → | West Ham UnitedWHU | Loan |
| 08 Mar 12 | F. Nouble Frank Nouble | West Ham UnitedWHU | → |  BarnsleyBAR | Loan |
| 06 Mar 12 | F. Piquionne Frédéric Piquionne | West Ham UnitedWHU | → |  Doncaster RoversDON | Loan |
| 24 Feb 12 | M. Stech Marek Stech | West Ham UnitedWHU | → |  Leyton OrientLEY | Loan |
| 17 Feb 12 | F. Sears Freddie Sears | West Ham UnitedWHU | → | Colchester UnitedCOL | Loan |
| 17 Feb 12 | O. Lee Oliver Lee | West Ham UnitedWHU | → |  GillinghamGIL | Loan |
| 08 Feb 12 | C. Montano Cristian Montano | West Ham UnitedWHU | → |  Notts CountyNOTT | Loan |
| 31 Jan 12 | R. Morrison Ravel Morrison |  Manchester UnitedMAN | → | West Ham UnitedWHU | Undisclosed |
| 31 Jan 12 | P. McCallum Paul McCallum | West Ham UnitedWHU | → |  RochdaleROCH | Loan |
| 31 Jan 12 | R. Vaz Te Ricardo Vaz Te | BarnsleyBAR | → | West Ham UnitedWHU | Undisclosed |
| 31 Jan 12 | R. Morrison Ravel Morrison | Manchester UnitedMAN | → | West Ham UnitedWHU | Undisclosed |
| 31 Jan 12 | N. Maynard Nicky Maynard | Bristol CityBRC | → | West Ham UnitedWHU | Undisclosed |
| 18 Jan 12 | Joe Dixon | XXX | → | West Ham UnitedWHU | Free |
| 13 Jan 12 | G. John George John |  FC DallasDAL | → | West Ham UnitedWHU | Loan |
| 13 Jan 12 | G. John George John | FC DallasDAL | → | West Ham UnitedWHU | Loan |
| 09 Jan 12 | G. Moncur George Moncur | West Ham UnitedWHU | → | AFC WimbledonWIM | Loan |
| 06 Jan 12 | C. McNaughton Callum McNaughton | West Ham UnitedWHU | → | AFC WimbledonWIM | Free |
| 06 Jan 12 | A. Abdulla Ahmed Abdulla | West Ham UnitedWHU | → |  Dagenham & RedbridgeD&R | Loan |
| 06 Jan 12 | E. Wearen Eoin Wearen | West Ham UnitedWHU | → | Dagenham & RedbridgeD&R | Loan |
| 05 Jan 12 | C. Driver Callum Driver | West Ham UnitedWHU | → |  Burton AlbionBRT | Loan |
| 02 Jan 12 | P. Kurucz Peter Kurucz | West Ham UnitedWHU | → | RochdaleROCH | Loan |