| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | O.R.B: Off-World Resource Base | PC | 1.0 | Original |  | 22434CD |  |
| Obduction | PC | 1.4.2 | Kickstarter |       | | |
| Obscure (Disc 1)
ObsCure | PC | 1.0 | Original | | PCO457CD | |
| Obscure (Disc 2)
ObsCure | PC | 1.0 | Original | | PCO457CD | |
| Obscure (Disc 3)
ObsCure | PC | 1.0 | Original | | PCO457CD | |
| Obscure (Disc 4)
ObsCure | PC | 1.0 | Original | | PCO457CD | |
| Obscure (Disc 5)
ObsCure | PC | 1.0 | Original | | PCO457CD | |
| Obsidian | PC | 1.0 | Demo | | | |
| Obsidian (Disc 1) | PC | | Original | | 11008 | |
| Obsidian (Disc 1) | PC | | Original, Complimentary Copy | | 11008 | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| Obsidian (Disc 2) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 3) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 4) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 5) | PC | | Original | | 11008 | |
| Obsidian (Disc 5) | PC | | Original, Complimentary Copy | | 11008 | |
| Oceans Below | PC | | Bundle Version OEM | | RVL 13-004-059 Rev. A / 2198610-590002 / I 083100 | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| Oddworld: Abe's Exoddus (Install) | PC | 2.0 | Original | | 04-15993CD1 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Channelware | | 04-15303 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | 04-12608CD | |
| Oddworld: Abe's Origins | PC | | Limited Run Games | | | |
| Odell Down Under | PC | | Original, SoftKey | | POD544AE-CD | |
| 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 | | Original | | | |
| ODS Robot Challenge | PC | 5.0.1r26 | Teacher's Edition | | | |
| 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 | | CD-C95-166-0 | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | CD-C95-166-1 | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | CD-C95-166-2 | |
| Off-Road Redneck Racing | PC | | Original | | CD-C98-1259-0 | |
| The Office | PC | | Original | | | |
| The Official Browser of Primagames.com | PC | | | | | |
| Official Duke Nukem 3D Level Design Handbook | PC | | Original | | 1869-0 | |
| The Official Guide to Babylon 5
The Official Guide to J. Michael Straczynski's Babylon 5 | PC | | Original | | | |
 | The Official Guide to The Daedalus Encounter: Companion Disc | PC | | Original | | | |
| Official Lara Croft: Real Life '99 Lara: Character Images | PC | | Press Kit | | | |
| Official Sega Dreamcast Magazine: Special Edition Preview PC CD-ROM | PC | | | | | |
| Ohio Distinctive Software Vol. I | PC | | | | | |
| Oil Tycoon | PC | 1.01 | Original | | | |
| Old El Paso Recipes for Family Fun | PC | | Original | | | |
 | Omar Sharif Bridge | PC | 1.0 | Original | | | |
| Omar Sharif on Bridge | PC | | Valueware | | CD-ICD-148-0 | |
| The Omega Stone: Riddle of the Sphinx II (Disc 1) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 2) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 3) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 4) | PC | 1.2.3.2 | Original | | | |
| 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 | | | |
| Ominous Horizons
Ominous Horizons: A Paladin's Calling | PC | 1.0 | Original | | | |
| One Must Fall 2097 | PC | | Original | | EPOMF01 | |
| One Must Fall 2097 | PC | | Original | | EPOMF01 | |
| One Must Fall 2097 | PC | 1.1 | Demo | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Unit Whole Blood | PC | 1.21 | Original | | 04-16459CD1 | |
| Oni | PC | 1.0 | Original | | | |
| Oni / 4x4 Evo
Oni / 4x4 Evolution | PC | | Demo | | 12DC1-09GM03-11 | |
| 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 | |
| Open Season (Disc 1) | PC | 1.0 | Original |  | 683131-CD1 | |
| Open Season (Disc 2) | PC | 1.0 | Original | | 683131-CD2 | |
| Open Season (Disc 3) | PC | 1.0 | Original | | 683131-CD3 | |
| Opening Night | PC | 1.0 | Original | | #HCD646A | |
| Opening Night: Behind The Scenes | PC | 1.0 | Original | | #HCD646B | |
| Operation | PC | | General Mills | | | |
| Operation | PC | | General Mills | | AM801R5 | |
| Operation | PC | | General Mills | | AM0703R71 | |
| 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 | | Playable Demo | | POPFCDUS40 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDUS00 | |
| Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original | | MOFUCDUS00 | |
| Operation Flashpoint: Red River | PC | | Original | | MOFP3CDUS00 | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDUS00 | |
| Operation Neptune | PC | 1.22 | Original | | ONT744CE-CD | |
| Operation Neptune | PC | 1.23 | The ClueFinders: Math Ages 9-12 | | ONT744EE-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: Century of Warfare | PC | | Original | | | |
| 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 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) (In the Lounge with No One Lives Forever) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ2 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | | |
| Opsys | PC | | Original | | | |
| Optimum Resource Sampler | PC | | Rerelease | | | |
| Optimum Resource Sampler | PC | | Original | | | |
| The Orange Box (Disc 2) | PC | | Original |      | 985217 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures | PC | 1.0 | DVD-ROM | | ORG811AE-DVD | |
| 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 1) | PC | 1.2 | Rerelease | | OTA744BE-CD1 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.2a | Bundle Version Compaq Presario OEM | | | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.3 | The Learning Company | | OAE744BE-CD1 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 2) | PC | | Original | | OTA744AE-CD2 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 2) | PC | 1.2 | Original | | OTA744BE-CD2 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 2) | PC | 1.3 | The Learning Company | | OAE744BE-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 3rd Edition: Pioneer Adventures (Disc 3) | PC | 1.2 | Original | | OTA744BE-CD3 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 3) | PC | 1.3 | The Learning Company | | OAE744BE-CD3 | |
| The Oregon Trail 4th Edition (Disc 1) | PC | 1 | Original | | OTF744AE-CD1 | |
| The Oregon Trail 4th Edition (Disc 1) | PC | 1.1 | Rerelease | | OTF744BE-CD1 | |
| The Oregon Trail 4th Edition (Disc 2) | PC | 1 | Rerelease | | OTF744CE-CD2 | |
| The Oregon Trail 4th Edition (Disc 2) | PC | 1 | Original | | OTF744AE-CD2 | |
| The Oregon Trail 4th Edition (Disc 2) | PC | 1.1 | Rerelease | | OTF744BE-CD2 | |
| The Oregon Trail 4th Edition (Disc 3) | PC | 1 | Original | | OTF744AE-CD3 | |
| The Oregon Trail 4th Edition (Disc 3) | PC | 1.1 | Rerelease | | OTF744BE-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 | 1.01E | Enhanced Education Version | | 480599-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 | Smart Saver | | 0TT744AE-CD | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 381032-CD/i401ha | |
| Oregon Trail II | PC | 1.31 | Rerelease | | HCD744BE-CD | |
| Oregon Trail II | PC | 1.31 | Rerelease | | #HCD744AE-CD | |
| Oregon Trail II | PC | 1.32 | Rerelease | | #HCD744CE-CD | |
| Oregon Trail II + Logic Quest | PC | 1.2/1.0 | Original | | | |
| Oregon Trail II: 25th Anniversary Limited Edition | PC | 1.3 | Original, SoftKey | | #OTR744AE-CD | |
| The Oregon Trail | PC | 1.0 | Original | | | |
| The Oregon Trail | PC | 1.1 | Original | | #HCD606 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.21 | | | | |
| The Oregon Trail | PC | 1.22 | Smart Saver | | ORT844AE-CD | |
| The Oregon Trail | PC | 3.0.1 | Slash | | CDRM1239790 | |
| The Oregon Trail: Classic Edition | PC | | SoftKey | | POT144EE-CD | |
| The Oregon Trail: Classic Edition | PC | | SoftKey | | POT144BE-CD | |
| The Oregon Trail: Classic Edition | PC | 3.0.1 | SoftKey | | POT144CE-CD | |
| Ori and the Blind Forest: Definitive Edition | PC | 5.3.2.9582331 | Limited Edition | | | |
| The Original Links | PC | | Solid Gold Edition | | | |
| The Original Mulan
花木兰 | PC | | Original | | | |
| The Orion Conspiracy | PC | 1.01 | Original | | | |
| Orly's Draw-A-Story | PC | | Original | | | |
 | Oro Negro: Juego de Guerra y Estrategia | PC | | Covermount | | | |
| Oscar Wilde's The Selfish Giant | PC | 2.10 | Original | | MQ 13-004-144 | |
| Othello | PC | | Original | | 99011 | |
 | Ouro e Glória: O Caminho para El Dorado | PC | | Original | | 906.02.0 | |
| Out of This World | PC | | Valueware | | CD-ICD-142-0 | |
| Out of This World | PC | | Rerelease | | CD-MMC-023-0 | |
| Outburst | PC | | Classic Value Series | | Product# 99043 | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| Outcast (Disc 2) | PC | | Original | | 42831-9110TC | |
| Outcry (Disc 1)
Outcry: The Dawn | PC | Version DPV 1.0 | Original | | PCO596CD | |
| Outcry (Disc 2)
Outcry: The Dawn | PC | Version DPV 1.0 | Original | | PCO596CD | |
| Outlast: A Reading for Information Game | PC | | Original | | HH824 | |
| Outlaws (Demonstration Program) | PC | Demo 1.0 CD Build 3 | Demo | | 644230 | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Bundle Version Diamond OEM | | 644430 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Bundle Version Diamond OEM | | 644431 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws: Cidade Sem Lei (Disc 1) | PC | 2.0 | Original | | 0806.05.0 | |
| Outlaws: Cidade Sem Lei (Disc 2) | PC | 2.0 | Original | | 0806.06.0 | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost | PC | | Original | | S725430 | |
| Outpost | PC | 1.1 | Rerelease | | S725431 | |
| Outpost | PC | 1.5 | Rerelease, Sierra Originals | | | |
| 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 (Disc 1) | PC | | Original | | | |
| OutRun 2006: Coast 2 Coast (Disc 2) | PC | | Original | | | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0298 Part No. X03-63527 | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0298 Part No. X03-57509 | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 1) | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 2) | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games: Volume II (Disc 1)
Over 1000 Games Volume 2 | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games: Volume II (Disc 2)
Over 1000 Games Volume 2 | PC | | Original | | | |
| Over 200 Programs for Windows
STG Computers LTD Windows Extra CD-ROM | PC | | Original | | | |
| Overlord | PC | 1.0 | Original | | MOVL1CDFC00 | |
| Overlord II | PC | | Preview Code |   | | |
| Overlord II | PC | 1.0 | Original | | MOVL2CDUS00 | |
| Overwatch | PC | | Game of the Year Edition, Legendary Edition | | 73052010US, S7302210 | |
| Owlboy (Game Disc) | PC | 0.0.6152.604 | IndieBox | | | |
| Oz: The Magical Adventure | PC | | Original | | | |
| Oz: The Magical Adventure | PC | 7.0.0.198 | Rerelease | | 92785 | |
| Ozzie's World | PC | | Original | | | |
