| 11316 | OTAN Alerta! + War Zone | ZX-Spectrum 48K | Spanish |
| 14274 | Ocean's Greatest Hits | ZX-Spectrum 48K | English |
| 11315 | Off the Hook | ZX-Spectrum 48K | English |
| 11966 | Office Master | ZX-Spectrum 48K | English |
| 20395 | Oglibloggs + Laser Defence | ZX-Spectrum 16K | English |
| 15477 | Oh Sh1t Another Big Disk | ZX-Spectrum 128 +3 | English |
| 3517 | On Cue | ZX-Spectrum 48K | English |
| 15478 | One More Big Disk | ZX-Spectrum 128 +3 | English |
| 12349 | One for the Road + Mutations | ZX-Spectrum 48K | English |
| 14976 | Opera Storys 1 | ZX-Spectrum 48K | Spanish |
| 15859 | Opera Super Sports | ZX-Spectrum 48K | Spanish |
| 27048 | Othello + Isola | ZX-Spectrum 16K | French |
| 15479 | Out of This World Vol. 1 | ZX-Spectrum 48K | English |
| 11317 | Over the Spectrum Cassette 1 | ZX-Spectrum 16K | English |
| 11318 | Over the Spectrum Cassette 2 | ZX-Spectrum 16K | English |
| 11974 | Over the Spectrum Cassette 3 | ZX-Spectrum 16K | English |
| 28051 | Overlord + Stalingrad | ZX-Spectrum 48K | English |
| 20409 | PAWS for Thought Vol 1 | ZX-Spectrum 128 +3 | English |
| 20410 | PAWS for Thought Vol 2 | ZX-Spectrum 128 +3 | English |
| 20411 | PAWS for Thought Vol 3 | ZX-Spectrum 128 +3 | English |