| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | O! Rety! Psoty Dudusia Wesołka | PC | | Playada Gier |  | P_20265_03A_PL |  |
 | O.D.T. | PC | | Dice |  | DCG 005509 | |
| O.D.T. | PC | | Original | | | |
 | O.D.T. | PC | | Original |  | | |
 | O.R.B: Off-World Resource Base | PC | 1.0 | Original | | 22434CD | |
 | Obbligato (Taikenban CD-ROM)
オブリガート 体験版CD-ROM | PC | | Demo |  | | |
 | Oblivious Garden: Carmina Burana (Disc 1) (Game Disk) | PC | 1.0 | Standard Edition |  | | |
| Oblivious Garden: Carmina Burana (Disc 2) (Music Disc) | PC | | Standard Edition | | | |
| ObsCure | PC | 1.0 | Original | | 719 02 102 | |
 | ObsCure | PC | | Original |  | | |
| ObsCure | PC | | Original |  | 71902134 | |
| ObsCure | PC | | Software Pyramide | | | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| ObsCure | PC | | Best of Atari | | | |
| ObsCure II | PC | | Original |  | | |
 | ObsCure II | PC | 1.0.0.0 | Original |  | | |
| Obsidian (Disc 1) | PC | | Original | | | |
| Obsidian (Disc 2) | PC | | Original | | | |
| Obsidian (Disc 3) | PC | | Original | | | |
| Obsidian (Disc 4) | PC | | Original | | | |
| Obsidian (Disc 5) | PC | | Original | | | |
| Oddworld: Abe's Exoddus (Install Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (Play Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (CD Installieren) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (CD Abspielen) | PC | 2.0 | Original | | | |
 | Oddworld: Abe's Exoddus (Disc 1) | PC | 1.0 | Covermount | | | |
| Oddworld: Abe's Exoddus (Disc 2) | PC | 1.0 | Covermount | | | |
 | Oddworld: Abe's Exoddus (Installazione) | PC | 1.0 | Replay | | ABEXPCREI/A1 | |
| Oddworld: Abe's Exoddus (Gioco) | PC | 1.0 | Replay | | ABEXPCREI/A2 | |
 | Oddworld: Abe's Exoddus (Play Disk) | PC | 2.0 | Budget | | MMICDR 5280 | |
| Oddworld: Abe's Exoddus (Installatie Disk) | PC | 2.0 | Budget | | MMICDR 5280 | |
| Oddworld: Abe's Exoddus (Install) | PC | | Original | | 04-15993CD1 | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | IB2G-ODD5 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | IB2G-ODDG5 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Covermount | | I62G-ODDI5 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | 04-12608CD | |
| Odell Down Under | PC | | Original | | POD544AE-CD | |
 | Odium | PC | | Covermount | | | |
| Odium
ōdi·um | PC | | Original | | CD-W58-1104-0 | |
| ODS Air Explorer | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Air Explorer | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Amazing Art Corner | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Carnival Math | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Carnival Math | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Robot Challenge | PC | 5.0.1r26 | Teacher's Edition | | | |
| Odyssee: Auf der Suche nach Odysseus (Disc 1) | PC | | Original | | ODY-GERCD1 | |
| Odyssee: Auf der Suche nach Odysseus (Disc 2) | PC | | Original | | ODY-GERCD2 | |
| Odyssey: The Search for Ulysses (Disc 1) | PC | | Original | | ODY-ENCD1 | |
| Odyssey: The Search for Ulysses (Disc 2) | PC | | Original | | ODY-ENCD2 | |
| Odyssey: The Search for Ulysses (Disc 1) | PC | | Original | | | |
| Odyssey: The Search for Ulysses (Disc 2) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 1) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | | |
| Off Limits: Mizar | PC | | ROMWARE | | ROM 10120 | |
| Off-Road Redneck Racing | PC | | Original | | CD-C98-1259-0 | |
| Offensive | PC | | Original | | | |
| The Office | PC | | Original | | | |
| Official Formula 1 Racing | PC | | Original | | | |
| The Official Guide to Babylon 5
The Official Guide to J. Michael Straczynski's Babylon 5 | PC | | Original | | | |
| Official Sega Dreamcast Magazine: Special Edition Preview PC CD-ROM | PC | | | | | |
| Offroad
Off-Road Redneck Racing | PC | | Original | | OFFPCCDML | |
| Offroad
Off-Road Redneck Racing | PC | | Original | | ECD 000592K | |
| Offroad Extreme! Special Edition | PC | | Original | | | |
| Ognisty Podmuch: Fire Captain (Disc 1) (Dysk Instalacyjny) | PC | | Covermount | | | |
| Ognisty Podmuch: Fire Captain (Disc 2) (Dysk z Grą) | PC | | Covermount | | | |
| Oldtimer: Erlebte Geschichte Teil II | PC | | Original | | | |
| Olympic Soccer | PC | | Kixx | | | |
| Omar Sharif Bridge | PC | 1.0 | Original | | | |
| Omerta: City of Gangsters | PC | | Covermount | | G1DVD0215 | |
| Omikron: The Nomad Soul (Disc 1) | PC | 1.0 | Original | | | |
| Omikron: The Nomad Soul (Disc 2) | PC | 1.0 | Original | | | |
| Omikron: The Nomad Soul (Disc 3) | PC | 1.0 | Original | | | |
| On the Ball: League Edition | PC | 1.0 | Original | | | |
| On the Ball: World Cup Edition | PC | 1.00 | Original | | | |
| One Must Fall 2097
One Must Fall 2097 CD-ROM | PC | 1.1 | ROMWARE | | ROM 10017 | |
| One Must Fall 2097 | PC | 2.1 | The Smile Edition | | CDR3016 | |
 | One Must Fall 2097 | PC | | Original | | | |
| One Must Fall 2097
One Must Fall | PC | | Rerelease | | D.L.: M-8684-97 | |
| One Must Fall 2097 | PC | 2.1 | Original | | EPOMF01 | |
| One Must Fall 2097 | PC | 2.1 | Original | | EPOMF01 | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Unit Whole Blood | PC | 1.21 | Original | | 04-16459CD1 | |
| Onegai Countdown
おねがいカウントダウン | PC | | Original | | YMH-0013 | |
| Oni | PC | 1.0 | Original | | | |
| Oni
ＯＮｉ 完全日本語版 ｆｏｒ Ｗｉｎｄｏｗｓ | PC | 1.00.000 | Original | | MTW-0390 | |
| Oni
Они | PC | 1.0 | | | | |
| Oni | PC | 1.0 | Original | | | |
| Onimusha 3 | PC | | Original | | 5004561 | |
| Onimusha 3: Demon Siege (Disc 1) | PC | | Original | | 683100-CD1 | |
| Onimusha 3: Demon Siege (Disc 2) | PC | | Original | | 683100-CD2 | |
| Onimusha 3: Demon Siege (Disc 3) | PC | | Original | | 683100-CD3 | |
| Oozora ni Kodawarou!: Minna no Kuukou 2
大空にこだわろう！ みんなの空港２ | PC | | | | | |
| Operation | PC | | General Mills | | | |
| Operation Body Count | PC | | Original | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDEU00 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Gold Edition | | MOPFCDEU00 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.46 | Sold Out Software | | | |
| Operation Flashpoint: Cold War Crisis | PC | | The Games Collection | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDUS00 | |
| Operation Flashpoint: Dragon Rising | PC | 1.0 | Original | | MOFP2CDEU00 | |
| Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original, Gold Edition | | MOFUCDEU00 | |
| Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original | | MOFUCDUS00 | |
| Operation Flashpoint: Holodnaja vojna
Операция Flashpoint: Холодная война | PC | 1.46 | | | | |
| Operation Flashpoint: Red River | PC | 1.0 | Original | | MOFP3CDEU00 | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDEU00 | |
| Operation Flashpoint: Soprotivlenie
Operation Flashpoint: Сопротивление | PC | 1.85 | | | | |
 | Operation Neptun | PC | 1.2 | Original |  | ONT844AW-CD | |
| Operation Neptune | PC | 1.22 | Original | | ONT744CE-CD | |
| 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 | |
| The Operational Art of War II: 1956-2000
The Operational Art of War II: Bewaffnete Konflikten | PC | | Original | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | FXX08903223D1 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition: BestSeller Series | | S0026178 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition | | | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | | |
 | The Operative: No One Lives Forever (Disc 2) | PC | 1.004 | Game of the Year Edition, Game of the Year Edition: BestSeller Series | | S0026179 | |
| 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 | | | |
| Opustoshenie
Опустошение | PC | 381 | Original | | | |
| The Orange Box (Disc 1) | PC | | Original |    | VAX07705811D | |
 | The Orange Box (Disc 2) | PC | | Original, EA Classics | | VAE07707118D2/ENG, VAX07705811D2, VAX07705811D2/AUS | |
 | 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 | | | |
| The Orange Box (Disc 1) | PC | | Original, EA Classics | | VAE07705811D, VAE07707118D/ENG, VAX07705811D/AUS | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.0 | Original | | OTA744AE-CD1 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.2 | Original | | OTA744CE-CD1 | |
| 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 4th Edition (Disc 1) | PC | 1 | Original | | OTF744AE-CD1 | |
| The Oregon Trail 4th Edition (Disc 2) | PC | 1 | Original | | OTF744AE-CD2 | |
| The Oregon Trail 4th Edition (Disc 3) | PC | 1 | Original | | OTF744AE-CD3 | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Original | | 380859-CD | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Scholastic | | 380859-CD WP2 | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Original | | 380859A-CD | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.1 | Rerelease, Southwestern School Set | | 380859B-CD | |
| Oregon Trail II | PC | 1.0 | Original | | | |
| Oregon Trail II | PC | 1.3 | Rerelease | | HCD744BE-CD | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 0TT744AE-CD | |
| Oregon Trail II | PC | 1.31 | Rerelease | | #HCD744AE-CD | |
| Oregon Trail II + Logic Quest | PC | 1.2/1.0 | Original | | | |
| Oregon Trail II: 25th Anniversary Limited Edition | PC | 1.3 | Original | | #OTR744AE-CD | |
| The Oregon Trail | PC | 1.0 | Original | | | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | | |
| The Oregon Trail | PC | 1.21 | | | | |
| The Oregon Trail | PC | 3.0.1 | Slash | | CDRM1239790 | |
| 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 | |
| The Original Links | PC | | Solid Gold Edition | | | |
| Original War (Disc 1) (Install Disc)
オリジナル ウォー | PC | 1.02 | Original | | | |
| Original War (Disc 2) (GameDisc)
オリジナル ウォー | PC | 1.02 | Original | | | |
| Orion Burger | PC | | Gold Games 2 (CD 11) | | SPI 046 | |
| Orion Burger | PC | | Abenteuer Doppelpack: Premier Collection | | MOBRLPGE72 | |
| Ortofrajda | PC | | | | | |
| Osada Avalona (Disc 1)
Осада Авалона | PC | | | | | |
| Osada Avalona (Disc 2)
Осада Авалона | PC | | | | | |
| Osananajimi ha Pet Yakuza!
幼なじみはペットヤクザ！体験版 | PC | | Taikenban | | | |
| Oscar | PC | | Golden Zone | | | |
| Oscar | PC | | Original | | | |
| Oscar the Balloonist: Discovers the Farm
小小探險家奧斯卡 農場奇遇記 | PC | | Original | | | |
| Othello | PC | | Original |  | | |
| Otome Koigokoro Prister
乙女恋心プリスター体験版 | PC | | Taikenban | | | |
| Otverzhennye: Tajna tjomnoj rasy (Disc 1)
Отверженные: Тайна тёмной расы | PC | | 1C: Игрушки (Tом 16) | | | |
| Out of This World | PC | | Valueware | | CD-ICD-142-0 | |
| Out of This World | PC | | Rerelease | | | |
| Outcast | PC | | Original | | | |
| Outcast (Disc 1) | PC | | Original | | OUTCAPC52G/A1 | |
| Outcast (Disc 2) | PC | | Original | | OUTCAPC52G/A2 | |
| Outcast (Disc 1) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 1) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A1 | |
| Outcast (Disc 2) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A2 | |
| Outcast (Disc 2) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 3) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A3 | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| Outcast (Disc 2) | PC | | Original | | 42831-9110TC | |
| Outer Ridge | PC | 1.0 | Original | | SPI004 | |
| The Outforce | PC | 1.0.0.0 | Original | | | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | LucasArts Classics | | 3000009.101.UK | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | LucasArts Classics | | 3000009.102.UK | |
| Outlaws (Disc 1) | PC | | Original | | | |
| Outlaws (Disc 2) | PC | | Original | | | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | | |
| Outlaws (Disc 1) | PC | 1.1 | Rerelease | | | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | | |
| Outlaws (Disc 2) | PC | 1.1 | Rerelease | | | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost | PC | | Original | | S390021012ZZ2 | |
| Outpost | PC | 1.51 | Schweinepreise | | S390122CZ12ZZ | |
| Outpost | PC | | Original | | S725430 | |
| Outpost | PC | 1.1 | Rerelease | | S725431 | |
| Outpost | PC | 1.5 | Rerelease | | | |
| Outpost 2: Destini Sospesi | PC | | Covermount | | | |
| Outpost 2: Divided Destiny | PC | | SierraOriginals | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| OutRun 2006: Coast 2 Coast | PC | | GSP White Label: Reload | | 1673A | |
| OutRun 2006: Coast 2 Coast | PC | | White Label | | 1673A | |
| OutRun 2006: Coast 2 Coast | PC | 1.0 | Original | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast | PC | | Gamer's Choice | | THQ70690 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0298 Part No. X03-63527 | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0298 Part No. X03-57509 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14039 DE | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14040 DE | |
 | Over 1000 Games: The Complete Encyclopedia of Games (Disc 1) | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 2) | PC | | Original | | | |
| Overboard! | PC | | Original | | | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| OverKill | PC | | ROMWARE | | ROM 10 007 | |
| Overlord | PC | 1.2 | Original | | MOVL1CDPL00 (DVD), POVL1CDPL03 (Box) | |
| Overlord II | PC | | Original | | MOVL2CDEU00 | |
 | Overwatch | PC | | Origins Edition | | | |
| Oxide
Oxyde | PC | | Dynamite | | DE-006 | |
| Oxyd Magnum! Gold Edition | PC | | Game-Pack 3 | | 80227 | |
| Oz: The Magical Adventure: Interactive Storybook | PC | 7.0.0.198 | Original | | 92785 | |
