| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | OnlineGamez | PC | | | | |  |
 | Only Fun: Entra anche tu nel mondo dei Videogames | PC | | | | | |
 | Only One + R: Higyaku no Mermaid Minano
オンリーワン＋Ｒ ～被虐のマーメイド美奈乃～ | PC | | Original |  | | |
| Only One 2: Bijin Casino Dealer Hitomi: Sei no Roulette
オンリーワン２ 美人カジノディーラー瞳 性のルーレット | PC | | Original | | ON2-HITO | |
| Only One 3in1
オンリーワン ３ｉｎ１ | PC | | PC Game Bundle | | | |
 | Onsalakorv | PC | | Original |  | | |
| Onsen de Takkyuu
温泉ｄｅ卓球 | PC | | Original | | | |
| Onsen Ping-Pong
温泉卓球 | PC | | Event Oyobi Tsuushin Hanbaiban | | | |
 | Ontdek de Boerderij met Barabas de Boekenbij | PC | | Original |  | | |
| Oozora ni Kodawarou! Minna no Kuukou 2
大空にこだわろう！ みんなの空港２ | PC | | | | | |
| Op Avontuur in de Molen | PC | | Original | | 5991 | |
| Op Avontuur in de Vuurtoren | PC | | Original | | 5990 | |
| Op Avontuur in het Piratenschip | PC | | Original | | 5989 | |
| Open Kart | PC | | I Videogiochi del "Giornalino" |  | | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
 | Open Season
Les Rebelles de la Forêt | PC | | Cheese Heads |   | | |
 | Open Season (Disc 1) | PC | | Original |   | 5004905-CD 1 | |
| Open Season (Disc 2) | PC | | Original | | 5004905-CD 2 | |
| Open Season (Disc 3) | PC | | Original | | 5004905-CD 3 | |
 | Open Season (Disc 1)
Сезон Охоты | PC | | Original |  | | |
| Open Season (Disc 2)
Сезон Охоты | PC | | Original | | | |
| Open Season (Disc 3)
Сезон Охоты | PC | | Original | | | |
| Opera Fatal | PC | | Tandem | | 1444 | |
| Opera Fatal | PC | | Original | | | |
| Opera House Preview Disc
オペラハウス プレビューディスク | PC | | Original | | | |
| Opera House Preview Disc #2
オペラハウス プレビューディスク ＃２ | PC | | Original | | | |
| Opera House Preview Disc #2.3
オペラハウス プレビューディスク ＃２．３ | PC | | Original | | | |
| Operaciya "Barbarossa"
Операция "Барбаросса" | PC | | Original | | | |
| Operaciya "Blau"
Операция "Блау" | PC | | Original | | | |
| Operaciya "Plastilin" (Disc 1)
Операция "Пластилин" | PC | | 1C: Kollekciya igrushek | | | |
| Operaciya "Plastilin" (Disc 2)
Операция "Пластилин" | PC | | 1C: Kollekciya igrushek | | | |
| Operaciya "X" ili novye piklyucheniya Shuricha (Disc 1)
Операция "Х" или новые приключения Шурича | PC | | 1C: Kollekciya igrushek | | | |
| Operaciya Bagration
Операция Багратион | PC | | Original | | | |
| Operaciya Silent Storm: Chasovye (Disc 1)
Операция Silent Storm: Часовые | PC | | 1C: Igroteka | | | |
| Operaciya Silent Storm: Chasovye (Disc 2)
Операция Silent Storm: Часовые | PC | | 1C: Igroteka | | | |
 | Operacja Pustynny Grom / The Partners | PC | | Covermount | | | |
| Operation | PC | | General Mills | | | |
 | Operation | PC | | General Mills | | AM801R5 | |
| Operation | PC | | General Mills | | AM0703R71 | |
| Operation AirStorm | PC | | Original | | 0860140921 | |
| Operation Barbarossa: The Struggle for Russia | PC | | Original | | | |
| Operation Blockade | PC | | Original | | 04-23965CD | |
| Operation Body Count | PC | | Original | | | |
| Operation Body Count | PC | | Original | | | |
| Operation Body Count: One Level Preview | PC | | Original | | | |
| Operation Europe: Path to Victory 1939-45 | PC | | Original | | | |
 | Operation Flashpoint: Cold War Crisis | PC | | The Games Collection | | | |
| Operation Flashpoint: Cold War Crisis | PC | | Playable Demo | | POPFCDUS40 | |
 | Operation Flashpoint: Dragon Rising | PC | | Original | | MOFP2CDEU00 | |
 | Operation Flashpoint: Gold Upgrade
Operace Flashpoint: Gold Upgrade | PC | | Original |  | | |
| Operation Flashpoint: Red River | PC | | Kakaku Kaiteihan | | FBG028W000A10 | |
| Operation Flashpoint: Red River | PC | | Original | | MOFP3CDUS00 | |
| Operation Mittelmeer | PC | | Original | | | |
| Operation Neptune + Reader Rabbit 2 Deluxe! + Ultimate Writing & Creativity Center
The Learning Company 3-in-1 | PC | | | | | |
| Operation Omega | PC | | Original | | 7-20286-92175-1 | |
| Operation: Surgery Has Never Been so Silly! | PC | | Replay Kids | | OPERPCREGB/A | |
| Operation: Surgery Has Never Been so Silly! | PC | | Sold Out Software | | | |
| The Operational Art of War II: 1956-2000
The Operational Art of War II: Bewaffnete Konflikten | PC | | Original | | | |
| The Operational Art of War: Century of Warfare | PC | | Original | | | |
| The Operational Art of War: Vol. 1: 1939-1955 | PC | | | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | | Game of the Year Edition | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ1, FXX08903223D1 | |
| The Operative: No One Lives Forever (Disc 2) (In the Lounge with No One Lives Forever) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ2 | |
| Opowieści z Narnii: Książe Kaspian | PC | | Covermount |  | | |
| Opowieści z Narnii: Lew, Czarownica i stara szafa
The The Chronicles of Narnia: The Lion Witch and The Wardrobe | PC | | Dookoła Filmu | | P_17791_03A_PL | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 1) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 2) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 3) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 4) | PC | | Original | | | |
| Opsys | PC | | Original |  | | |
| Opsys | PC | | Original | | | |
| Optimum Resource Sampler | PC | | Rerelease | | | |
| Optimum Resource Sampler | PC | | Original | | | |
| The Orange Box (Disc 1) | PC | | Original |     | VAX07705811D | |
| The Orange Box (Disc 1) | PC | | Original, EA Value Games | | VAD07705811D | |
| The Orange Box (Disc 2) | PC | | Original, EA Value Games | | VAD07705811D2 | |
| The Orange Box (Disc 1) | PC | | Original | | VAI07705811D | |
| The Orange Box (Disc 2) | PC | | Original | | VAI07705811D2 | |
| The Orange Box (Disc 1) | PC | | Rerelease | | | |
| The Orange Box (Disc 1) | PC | | Original |    | | |
| The Orange Box (Disc 2) | PC | | Rerelease | | | |
| The Orange Box (Disc 2) | PC | | Original | | | |
 | The Orange Box (Disc 1)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original | | TTE0193 | |
| The Orange Box (Disc 2)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original | | TTE0193 | |
| The Orange Box (Disc 2) | PC | | Original | | 985217 | |
 | The Orange Box (Disc 1) | PC | | Original, EA Classics | | 985207, VAE07705811D, VAE07705811D/ENG, VAE07707118D/ENG, VAX07705811D/AUS | |
 | The Orange Box (Disc 2) | PC | | Original, EA Classics | | VAE07705811D2/ENG, VAE07707118D2/ENG, VAX07705811D2, VAX07705811D2/AUS | |
| Orchid Technology Kelvin MPEG Software Catalog | PC | | | | | |
| Orcs Must Die! | PC | | Original | | | |
| Orda: Severnyj veter
Орда: Северный ветер | PC | | Original | | | |
| Order of War | PC | | Original | | OOW/LAB1 | |
| Order of War: Osvobozhdenie
Order of War: Освобождение | PC | | Igromaniya: Vybor redakcii | | | |
| Order of War: Stolknovenie
Order of War: Столкновение | PC | | Igromaniya: Vybor redakcii | | | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 2) | PC | | Original | | OTA744AE-CD2 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 3) | PC | | Original | | OTA744AE-CD3 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 3) | PC | | Original | | OTA744AE-CD3 | |
| The Oregon Trail: Classic Edition | PC | | SoftKey | | POT144EE-CD | |
| The Oregon Trail: Classic Edition | PC | | SoftKey | | POT144BE-CD | |
| The OrganWise Guys: OrganWise-ology Game | PC | | Original | | | |
| Orgaslave (Side-1)
オルガスレイブ | PC | | Original | | H PT 003-1 | |
| Orgaslave (Side-2)
オルガスレイブ | PC | | Original | | H PT 003-2 | |
