| GAMELIST | Operation Wolf | 1988 |
| GAMELIST | Operation Thunderbolt (GX4000) | 1990 |
| GAMELIST | Operation Thunderbolt | 1989 |
| GAMELIST | Operation Program Cleaner | 1991 |
| GAMELIST | Operation Hormuz | 1989 |
| GAMELIST | Operation Hanoi | 1990 |
| GAMELIST | Operation Gunship | 1989 |
| GAMELIST | Operation Desert Storm | 1995 |
| GAMELIST | Operation Colossus | 1985 |
| APPLICATIONS | Operation Caretaker (Alignment+ Program/Kit de mantenimiento)  | 198x |
| GAMELIST | Operation Barbarossa | 1989 |
| GAMELIST | Operation Alexandra (1st CPCRetroDev 2018) | 2018 |
| GAMELIST | Open Tower Defense | 2021 |
| DEMOSCENE | Onescreen Colonies #4 (Vanity) | 2025 |
| DEMOSCENE | Onescreen Colonies #3 (Vanity) | 2023 |
| DEMOSCENE | Onescreen Colonies #2 (Vanity) | 2022 |
| GAMELIST | One-on-one | 1985 |
| DEMOSCENE | One-line Irish Washer-woman (Amstrad Action) | 1991 |
| APPLICATIONS | One-line Entertainer | 1988 |
| GAMELIST | One Wonder (CPCRetroDev 2023) | 2023 |
| GAMELIST | One Man and His Droid | 1985 |
| APPLICATIONS | One Dimensional Automata (Computing with the Amstrad) | 1987 |
| GAMELIST | One | 1986 |
| GAMELIST | Once a Knight is Enough | 1991 |
| DEMOSCENE | On-Screen Effects On the CPC464 (Popular Computing Weekly) | 1984 |
| GAMELIST | On the Run | 1985 |
| LITTÉRATURE | On the Road to Artificial Intelligence | 1985 |
| GAMELIST | On the Oche | 1984 |
| GAMELIST | On the Bench | 1988 |
| APPLICATIONS | On File Database Management System  | 2024 |
| GAMELIST | On Cue | 1987 |
| HARDWARE | Omni-Reader | 1987 |
| DEMOSCENE | Omicron Demo | 1990 |
| APPLICATIONS | Omicron | 198x |
| GAMELIST | Omeganea | 1986/1987 |
| APPLICATIONS | Omega Scroll (Amstrad Computer User) | 1991 |
| GAMELIST | Olympiad '86 | 1986 |
| GAMELIST | Olli And Lissa: The Ghost of Shilmoore Castle | 1987 |
| GAMELIST | Olli And Lissa 3: The Candlelight Adventure | 1989 |
| GAMELIST | Oliver Rand | 1985 |
| GAMELIST | Old West | 2021 |
| GAMELIST | Old Scores | 1986 |
| GAMELIST | Old Sam's Saloon Gamble Machine | 1989 |
| DEMOSCENE | OK! Part (Cybord Megademo Preview) | 19xx |
| GAMELIST | Oink! | 1987 |
| GAMELIST | Oilmania | 1990 |
| GAMELIST | OIK | 1988/1989 |
| GAMELIST | OH NO, My Moustache! | 2022 |
| GAMELIST | Oh Mummy
Oh Momies!
Schatz der Pharaonen | 1984 |
| GAMELIST | Oh Mummy Resurrected | 1984/2025 |
| GAMELIST | Oh Chute! | 2024 |
| GAMELIST | Off Shore Warrior | 1989 |
| SLIDESHOW | Odyssey | 1994 |
| GAMELIST | Odds | 1985 |
| GAMELIST | Odd One Out (Amstrad Computer User) | 19xx |
| GAMELIST | Octopus GX4000 | 2023 |
| GAMELIST | Octopus Deluxe | 2023 |
| GAMELIST | Octopus 21 | 2023 |
| GAMELIST | Octopus | 2021 |
| GAMELIST | Octoplex | 1989 |
| DEMOSCENE | October 95 | 1995 |
| DEMOSCENE | OctoBear's 3D-Scroll-Intro | 1992 |
| APPLICATIONS | Ocp Screens Viewer | 1998 |
| APPLICATIONS | OCP à la Loupe (ACPC n°27) | 1990 |
| APPLICATIONS | OCP à la Loupe (ACPC n°26) | 1990 |
| APPLICATIONS | OCP à la Loupe (ACPC n°22) | 1990 |
| APPLICATIONS | OCP à la Loupe (ACPC n°21) | 1989 |
| APPLICATIONS | OCP à la Loupe (ACPC n°20) | 1989 |
| APPLICATIONS | OCP à la Loupe (ACPC n°19) | 1989 |
| APPLICATIONS | OCP à la Loupe (ACPC n°18) | 1989 |
| GAMELIST | Oceano | 2015 |
| LITTÉRATURE | Ocean the History | 2014 |
| GAMELIST | Ocean Conqueror | 1988 |
| GAMELIST | Obstacle (Amstrad Games Book) | 1985 |
| GAMELIST | Obsidian
L'hepiss | 1985 |
| GAMELIST | Obliterator | 1989 |
| GAMELIST | Oberon 69 | 1990 |
| GAMELIST | O Grady Says | 1984 |
| GAMELIST | Nythyhel: Files of the Occult | 1986 |
| GAMELIST | NWO (27th @ CPCRetroDev 2015) | 2015 |
| APPLICATIONS | NWC Demomaker | 198x |
| DEMOSCENE | NWC - Falcon | 1989/1990/1991 |
| GAMELIST | Numbers Up | 1986 |
| APPLICATIONS | Numbers | 1984 |
| GAMELIST | Numbercircle | 1990 |
| GAMELIST | NumberBlaster (Amstrad Action) | 1991 |
| GAMELIST | Number Swop / Puzzle (Popular Computing Weekly) | 1984 |
| GAMELIST | Number Shooter (Amstrad Action) | 1993 |
| GAMELIST | Number Series | 1990 |
| GAMELIST | Number Scoffer (Amstrad Action) | 1992/1993 |
| GAMELIST | Number Painter | 1984 |
| GAMELIST | Number game | 1987 |
| APPLICATIONS | Number Filer v2 (W.A.C.C.I) | 199x |
| APPLICATIONS | Number Filer v1 (Amstrad Action) | 1991 |
| APPLICATIONS | Number Extension (Amstrad Action) | 1991 |
| APPLICATIONS | Number Base Changer (Amstrad Computer User) | 1991/1992 |
| GAMELIST | Number 11
Sum Fun | 198x |
| GAMELIST | Number 1 | 1985 |
| APPLICATIONS | NULU | 1984/1985/1986 |
| GAMELIST | Nuke Bug (CPCRetroDev 2023) | 2023 |
