| DEMOSCENE | Overflow Tome 1 | 1990 |
| GAMELIST | Overdrive | 1985 |
| DISCMAG | Ovation 5 (Another World fanzine) | 1999 |
| DISCMAG | Ovation 4: The Insane Issue! | 1997 |
| DISCMAG | Ovation 3 | 1997 |
| DISCMAG | Ovation 2 | 1996 |
| DISCMAG | Ovation 1 | |
| GAMELIST | Outlaws (1st @ CPCRetroDev 2016)
Outlaws Reloaded | 2016/2017 |
| GAMELIST | Outlaw | 1990 |
| APPLICATIONS | Outch Noter Text Ripper | 1997 |
| APPLICATIONS | Outch Noter | 1996 |
| GAMELIST | Out Run Europa
OutRun Europa | 1991 |
| GAMELIST | Out Run | 1987 |
| GAMELIST | Out of this World (Andrew Richards) | 1987/2016/ |
| GAMELIST | Out of this World | 1987 |
| DISCMAG | Otto 5 | 1996/1997 |
| DISCMAG | Otto 4 | 1996 |
| DISCMAG | Otto 3 | 1996 |
| DISCMAG | Otto 2 | 1996 |
| DISCMAG | Otto 1 | 1995 |
| GAMELIST | Othello (Computing with the Amstrad) | 1986 |
| GAMELIST | Othello (Computer Challenges for the Amstrad)  | 1985 |
| GAMELIST | Osprey! | 1984 |
| GAMELIST | Osotos | 2024 |
| GAMELIST | Oscar in a Jam | 1985/1986 |
| GAMELIST | Ormen Slange | 1987/2018 |
| GAMELIST | Orion Prime | 2009 |
| CODING SRC'S | Origins (Computing With the Amstrad) | 1985 |
| GAMELIST | Oriental Games | 1990 |
| APPLICATIONS | Orgams | 2015/2016/2017/2018/... |
| GAMELIST | Orc's Lair (The Amstrad Games Book) | 1984 |
| GAMELIST | Orb Quest | 1990 |
| APPLICATIONS | Orakel (CPC Amstrad International) | 1987 |
| APPLICATIONS | Optimize ROM | 1990 |
| GAMELIST | OPQA vs. QAOP: The Final Battle (5th CPCRetroDev 2018) | 2018 |
| LITTÉRATURE | Operators and Programmers Guide for the Amstrad CPC6128 and PCW 8256 | 198x |
| GAMELIST | Operation Wolf (version Magnum Lightphaser) | 1988 |
| GAMELIST | Operation Wolf: Plusedition | 20xx |
| 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 | 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 |
