| 3548 | Orion | ZX-Spectrum 48K | English |
| 24852 | Orion Quest | ZX-Spectrum 48K | English |
| 29604 | Orion Shuttle | ZX81 1K | English |
| 22055 | Orkenvandringen | ZX-Spectrum 48K | English |
| 9150 | Orm and Cheep: Narrow Squeaks | ZX-Spectrum 48K | English |
| 9151 | Orm and Cheep: The Birthday Party | ZX-Spectrum 48K | English |
| 10018 | Orpheus | ZX-Spectrum 16K | English |
| 10019 | Orpheus in the Underworld | ZX-Spectrum 16K | English |
| 10021 | Orsis | ZX-Spectrum 48K | English |
| 26726 | Orthius | ZX-Spectrum 16K | English |
| 2001468 | Osborne CP/M User Guide | - | English |
| 22041 | Oscar 13 | ZX-Spectrum 48K | English |
| 36033 | Oscar10 | ZX81 16K | English |
| 27144 | Oscylograf | ZX-Spectrum 48K | English |
| 43608 | Osotos | ZX-Spectrum 48K/128K | English |
| 25541 | Osprey! | ZX-Spectrum 48K | English |
| 28156 | Ossuary | ZX-Spectrum 16K | English |
| 3550 | Ostron | ZX-Spectrum 16K | English |
| 3554 | Othello | ZX-Spectrum 16K | English |
| 25600 | Othello | ZX-Spectrum 48K | English |