Region | Title | System | Version | Edition | Languages | Serial | Status |
| Obsidian (Disc 1) | PC | | Original | | 11008 | |
| Obsidian (Disc 1) | PC | | Original, Complimentary Copy | | 11008 | |
| 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 | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| 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 Robot Challenge | PC | | Original | | | |
| 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 | |
| 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 | | | | | |
| Old El Paso Recipes for Family Fun | PC | | Original | | | |
| Omar Sharif on Bridge | PC | | Valueware | | CD-ICD-148-0 | |
| One Must Fall 2097 | PC | | Original | | EPOMF01 | |
| Oni / 4x4 Evo Oni / 4x4 Evolution | PC | | Demo | | 12DC1-09GM03-11 | |
| Operation | PC | | General Mills | | AM801R5 | |
| Operation Body Count: One Level Preview | PC | | Original | | | |
| Operation Flashpoint: Cold War Crisis | PC | | Playable Demo | | POPFCDUS40 | |
| 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 2) (In the Lounge with No One Lives Forever) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ2 | |
| 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 (Disc 2) | PC | | Original | | OTA744AE-CD2 | |
| 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 Original Mulan 花木兰 | PC | | Original | | | |
| Orly's Draw-A-Story | PC | | Original | | | |
| Oro Negro: Juego de Guerra y Estrategia | PC | | Covermount | | | |
| Ouro e Glória: O Caminho para El Dorado | PC | | Original | | 906.02.0 | |
| Outburst | PC | | Classic Value Series | | Product# 99043 | |
| Outlast: A Reading for Information Game | PC | | Original | | HH824 | |
| Outpost | PC | | Original | | S725430 | |
| 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 II | PC | | Preview Code | | | |
| Overwatch | PC | | Game of the Year Edition, Legendary Edition | | 73052010US, S7302210 | |
| Oz: The Magical Adventure | PC | | Original | | | |
| Ozzie's World | PC | | Original | | | |
| Owlboy (Game Disc) | PC | 0.0.6152.604 | IndieBox | | | |
| The Oregon Trail 4th Edition (Disc 1) | PC | 1 | Original | | OTF744AE-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 3) | PC | 1 | Original | | OTF744AE-CD3 | |
| ObsCure (Disc 1) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 2) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 3) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 4) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 5) | PC | 1.0 | Original | | PCO457CD | |
| Obsidian | PC | 1.0 | Demo | | | |
| Omar Sharif Bridge | PC | 1.0 | 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 | | | |
| Opening Night | PC | 1.0 | Original | | #HCD646A | |
| Opening Night: Behind The Scenes | PC | 1.0 | Original | | #HCD646B | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | | |
| 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 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 | |
| Oregon Trail II | PC | 1.0 | Original | | | |
| 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 2) | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Bundle Version Diamond OEM | | 644431 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition | | | |
| Oil Tycoon | PC | 1.01 | Original | | | |
| The Orion Conspiracy | PC | 1.01 | Original | | | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.01E | Enhanced Education Version | | 480599-CD | |
| The Oregon Trail 4th Edition (Disc 1) | PC | 1.1 | Rerelease | | OTF744BE-CD1 | |
| The Oregon Trail 4th Edition (Disc 2) | PC | 1.1 | Rerelease | | OTF744BE-CD2 | |
| The Oregon Trail 4th Edition (Disc 3) | PC | 1.1 | Rerelease | | OTF744BE-CD3 | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.1 | Rerelease, Southwestern School Set | | 380859B-CD | |
| The Oregon Trail | PC | 1.1 | Original | | #HCD606 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.2 | Rerelease | | OTA744BE-CD1 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 2) | PC | 1.2 | Original | | OTA744BE-CD2 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 3) | PC | 1.2 | Original | | OTA744BE-CD3 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Operation Neptune | PC | 1.22 | Original | | ONT744CE-CD | |
| The Oregon Trail | PC | 1.22 | Smart Saver | | ORT844AE-CD | |
| Operation Neptune | PC | 1.23 | The ClueFinders: Math Ages 9-12 | | ONT744EE-CD | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.2a | Bundle Version Compaq Presario OEM | | | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 0TT744AE-CD | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 381032-CD/i401ha | |
| Oregon Trail II: 25th Anniversary Limited Edition | PC | 1.3 | Original, SoftKey | | #OTR744AE-CD | |
| 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 | |
| Obduction | PC | 1.4.2 | Kickstarter | | | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDUS00 | |
| 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 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| 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 | |
| Oscar Wilde's The Selfish Giant | PC | 2.10 | Original | | MQ 13-004-144 | |
| The Oregon Trail: Classic Edition | PC | 3.0.1 | SoftKey | | POT144CE-CD | |
| ODS Robot Challenge | PC | 5.0.1r26 | Teacher's Edition | | | |
| 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 | | | |
| Ori and the Blind Forest: Definitive Edition | PC | 5.3.2.9582331 | Limited Edition | | | |
| Outlaws (Demonstration Program) | PC | Demo 1.0 CD Build 3 | Demo | | 644230 | |
| 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 | |