| 19 Oct 10 | F. Sears Freddie Sears |  West Ham UnitedWHU | → |  Scunthorpe UnitedSCU | Loan |
| 19 Oct 10 | F. Sears Freddie Sears | West Ham UnitedWHU | → | Scunthorpe UnitedSCU | Loan |
| 17 Sept 10 | F. Nouble Frank Nouble | West Ham UnitedWHU | → |  Swansea CitySWA | Loan |
| 17 Sept 10 | F. Nouble Frank Nouble | West Ham UnitedWHU | → | Swansea CitySWA | Loan |
| 31 Aug 10 | R. Boffin Ruud Boffin |  MVV MaastrichtMVV | → | West Ham UnitedWHU | Undisclosed |
| 31 Aug 10 | L. Jacobsen Lars Jacobsen |  Blackburn RoversBLK | → | West Ham UnitedWHU | Free |
| 30 Aug 10 | F. Daprelá Fabio Daprelá | West Ham UnitedWHU | → |  BresciaBRE | Undisclosed |
| 30 Aug 10 | F. Daprelá Fabio Daprelá | West Ham UnitedWHU | → | BresciaBRE | Undisclosed |
| 27 Aug 10 | V. Obinna Victor Obinna |  InternazionaleINT | → | West Ham UnitedWHU | Loan |
| 27 Aug 10 | V. Obinna Victor Obinna | InternazionaleINT | → | West Ham UnitedWHU | Loan |
| 24 Aug 10 | A. Diamanti Alessandro Diamanti | West Ham UnitedWHU | → | BresciaBRE | 1800000 |
| 24 Aug 10 | A. Diamanti Alessandro Diamanti | West Ham UnitedWHU | → | BresciaBRE | 1800000 |
| 05 Aug 10 | W. Reid Winston Reid |  FC MidtjyllandMIDT | → | West Ham UnitedWHU | Undisclosed |
| 05 Aug 10 | M. Fry Matthew Fry | West Ham UnitedWHU | → |  Charlton AthleticCHA | Loan |
| 03 Aug 10 | T. Ben Haim Tal Ben Haim |  PortsmouthPOR | → | West Ham UnitedWHU | Loan |
| 03 Aug 10 | T. Ben Haim Tal Ben Haim | PortsmouthPOR | → | West Ham UnitedWHU | Loan |
| 16 Jul 10 | P. Barrera Pablo Barrera |  Pumas UNAMUNAM | → | West Ham UnitedWHU | 4000000 |
| 16 Jul 10 | P. Barrera Pablo Barrera | Pumas UNAMUNAM | → | West Ham UnitedWHU | 4000000 |
| 16 Jul 10 | F. Piquionne Frédéric Piquionne |  LyonLYON | → | West Ham UnitedWHU | Undisclosed |
| 16 Jul 10 | F. Piquionne Frédéric Piquionne | LyonLYON | → | West Ham UnitedWHU | Undisclosed |
| 05 Jun 10 | T. Hitzlsperger Thomas Hitzlsperger |  LazioLAZ | → | West Ham UnitedWHU | Free |
| 05 Jun 10 | T. Hitzlsperger Thomas Hitzlsperger | LazioLAZ | → | West Ham UnitedWHU | Free |
| 24 May 10 | B. Ngala Bondz Ngala | West Ham UnitedWHU | → |  Plymouth ArgylePLY | Free |
| 24 May 10 | B. Ngala Bondz Ngala | West Ham UnitedWHU | → | Plymouth ArgylePLY | Free |
| 25 Mar 10 | M. Fry Matthew Fry | West Ham UnitedWHU | → | Charlton AthleticCHA | Loan |
| 19 Mar 10 | F. Nouble Frank Nouble | West Ham UnitedWHU | → |  Swindon TownSWI | Loan |
| 15 Mar 10 | B. Ngala Bondz Ngala | West Ham UnitedWHU | → | Plymouth ArgylePLY | Loan |
| 15 Mar 10 | B. Ngala Bondz Ngala | West Ham UnitedWHU | → | Plymouth ArgylePLY | Loan |
| 11 Feb 10 | F. Sears Freddie Sears | West Ham UnitedWHU | → |  Coventry CityCOV | Loan |
| 11 Feb 10 | F. Sears Freddie Sears | West Ham UnitedWHU | → | Coventry CityCOV | Loan |
| 09 Feb 10 | F. Nouble Frank Nouble | West Ham UnitedWHU | → |  West Bromwich AlbionWBA | Loan |
| 09 Feb 10 | F. Nouble Frank Nouble | West Ham UnitedWHU | → | West Bromwich AlbionWBA | Loan |
| 01 Feb 10 | A. Ilan Aruajo Ilan | XXX | → | West Ham UnitedWHU | Free |
| 01 Feb 10 | A. Mido Ahmed Hossam Mido |  MiddlesbroughMID | → | West Ham UnitedWHU | Loan |
| 01 Feb 10 | B. McCarthy Benedict McCarthy | Blackburn RoversBLK | → | West Ham UnitedWHU | Undisclosed |
| 01 Feb 10 | A. Mido Ahmed Hossam Mido | MiddlesbroughMID | → | West Ham UnitedWHU | Loan |
| 22 Jan 10 | J. Payne Josh Payne | West Ham UnitedWHU | → |  Wycombe WanderersWYC | Loan |
| 22 Jan 10 | N. Quashie Nigel Quashie | West Ham UnitedWHU | → |  Queens Park RangersQPR | Free |
| 22 Jan 10 | N. Quashie Nigel Quashie | West Ham UnitedWHU | → | Queens Park RangersQPR | Free |
| 09 Jan 10 | H. Eyjolffson Holmar Orn Eyjolffson | West Ham UnitedWHU | → | RXXRoeselareRoeselare | Loan |