| getit | Maker | Status | Projects | Rating | Lang | Years | Additional Comments |
| - | o'Moses | ? | 1 Game | 21% | - | 1996 | - |
| - | Oase (now called Arktis) | Dead | 6 Games, 1 Reference | 62% | de | 1992-1993 | - |
 | Ocean URL (bought by Infogrames) | Dead | 83 Games, 1 Reference, 13 CDs | 71% | en | 1987-1996? | Have released tons of excellent Amiga games. Now they're unfortunately out of the business. |
| - | Odyssey | ? | 2 Games, 2 CDs | 46% | - | 1990-1991? | - |
| - | Off the Wall Productions | ? | 1 Game | 70% | - | 1990 | - |
| - | Offence Software | ? | 1 Game | 72% | - | 1992 | - |
| - | Ola Zandelin | ? | 2 Games | 56% | - | 1995? | - |
| - | Olaf Otterbach | ? | 1 Game | 10% | - | 1989 | - |
| - | Olaf Schneider | ? | 1 Game | 42% | - | 1987 | - |
| - | Olaf Seibert | ? | 1 Game | 52% | - | 1993 | - |
| - | Old Miller | ? | 3 Games | - | - | 1994? | - |
| - | Olethros | ? | 1 Game | 52% | - | 1997 | - |
| - | Oliver Michel | ? | 2 Games | 62% | - | ? | - |
| - | Oliver Schwald | ? | 1 Game | 10% | - | 1987 | - |
| - | Oliver Seidel | ? | 1 Game | - | - | 1994 | - |
| - | Oliver Wagner | ? | 2 Games | 34% | - | 1988-1994 | - |
| - | Olivier Lux | ? | 1 Game | 36% | - | ? | - |
| - | Olympia Entertainment | ? | 1 Game | 71% | - | 1996 | - |
| - | Olympian Software | ? | 1 Game | - | - | 1990 | - |
| - | Omega Demos Inc. | ? | 1 Game | 59% | - | 1992 | - |
| - | Omnitrend Software | ? | 6 Games | 58% | - | 1987-1993 | - |
| - | OMT | ? | 1 Game | - | - | 1995 | - |
| - | On the Dole Software | Active | 4 Games | 60% | - | 1999-2001 | - |
| On-line Entertainment URL | Active | 2 Games, 10 CDs | 51% | en | 1991-1993? | Creators of Amiga games like Challenge Golf or Chaos in Andromeda. |
| - | Only Games | ? | 2 Games | 53% | - | 1990? | - |
| - | Onyxsoft | ? | 1 Game | 5% | - | 1996 | - |
| - | Opera Soft | Dead | 5 Games | 52% | - | 1990? | - |
| - | Operating German System | ? | 1 Game | 35% | - | 1992 | - |
| - | Optimus Software | ? | 2 Games | 58% | - | 1991-1992 | - |
| Origin URL (part of Electronic Arts) | Active | 12 Games, 1 Demo, 1 Reference, 5 CDs | 69% | en | 1986-1993? | Lord British's ultima(te) company. |
| - | Oscarsoft | ? | 2 Games | 34% | - | 1989 | - |
| - | OTM Publications | ? | 1 Game, 1 CD | 56% | - | 1994? | - |
| - | Ouija Board | ? | 1 Game | 69% | - | 1995 | - |
| - | Outlaw | ? | 1 Game | 58% | - | 1989 | - |
| - | Overdose | ? | 2 Games | 50% | - | ? | - |
| - | Overflow Productions | ? | 5 Games | 42% | - | 1995-1997? | - |
| - | Owl | ? | 2 Games | - | - | 1993? | - |
| - | Oxford Digital Enterprises | ? | 1 Game | 32% | - | 1990 | - |
| - | Oxford Mobius | ? | 1 Game | 48% | - | 1989 | - |
| Oxford Softworks URL (now called Purple Software) | Active | 9 Games, 1 Reference | 64% | en | 1989-1994 | Oxford Softworks is a development and publishing software house based in Oxfordshire, England. Since the very birth of the leisure software industry, the company |
| - | Oxygen | Dead | 1 Game, 1 Demo | 60% | - | 1991-1993 | - |
| Oxyron URL | Active | 3 Games, 8 Demos, 2 CDs | 65% | de,en | 1993-2003 | Oxyron Software has made cool Amiga games as well as many outstanding demos. |
| - | Ozehn | ? | 1 Game | 23% | - | ? | - |
| - | Ozisoft (now called Sega Australia) | Dead | 1 Game, 1 Reference | - | en | 1988 | - |
| getit | Maker | Status | Projects | Rating | Lang | Years | Additional Comments |
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