| getit | Maker | Status | Projects | Rating | Lang | Years | Additional Comments |
| - | Oberland | ? | 3 CDs | - | - | 1994-1995? | - |
 | 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? | - |
| - | Olliweb | ? | 1 CD | - | - | 2000 | - |
| On-line Entertainment URL | Active | 2 Games, 10 CDs | 51% | en | 1991-1993? | Creators of Amiga games like Challenge Golf or Chaos in Andromeda. |
| - | Optonica | ? | 4 CDs | - | - | 1993-1995 | - |
| 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. |
| - | OTM Publications | ? | 1 Game, 1 CD | 56% | - | 1994? | - |
| 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. |
| getit | Maker | Status | Projects | Rating | Lang | Years | Additional Comments |
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