Region | Title | System | Version | Edition | Languages | Serial | Status |
| Oceans Below The Software Toolworks Presents ... Oceans Below | MAC | | Original | | 2198620-590001 / I 073100, CDRM1103420 | |
| Online Start-Up Disc v1.0 Disco de Inicio en Línea v1.0 | PS2 | 1.00 | Original | | PBPX 95250 … | |
| Oregon Trail II | PC | 1.31 | Rerelease | | HCD744BE-CD | |
| O.D.T. | PSX | | Original | | SLUS-00698 | |
| O.D.T. | PSX | | Demo | | SLUS-90043 | |
| 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, Complimentary Copy | | 11008 | |
| Oceans Below | 3DO | | Original | | | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| Oddworld: Abe's Exoddus (Install) | PC | 2.0 | Original | | 04-15993CD1 | |
| Oddworld: Abe's Exoddus (Disc 1) | PSX | | Original | | SLUS-00710 … | |
| Oddworld: Abe's Exoddus (Disc 2) | PSX | | Original | | SLUS-00731 … | |
| Oddworld: Abe's Oddysee | PSX | | Original | | SLUS-00190 | |
| Oddworld: Abe's Oddysee | PSX | | Demo | | SLUS-90004 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | 04-12608CD | |
| Oddworld: Abe's Oddysee | PSX | Rev 1 | Original, Greatest Hits | | SLUS-00190 | |
| Oddworld: Abe's Oddysee | PSX | Rev 2 | Greatest Hits | | SLUS-00190 | |
| Odell Down Under | PC | | Original, SoftKey | | POD544AE-CD | |
| Odium ōdi·um | PC | | Original | | CD-W58-1104-0 | |
| ODS Robot Challenge | PC | 5.0.1r26 | Teacher's Edition | | | |
| Off-World Interceptor Extreme | PSX | | Original | | SLUS-00020 | |
| 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 | | | | | |
| Official U.S. PlayStation Magazine Demo Disc 01 | PSX | | | | SCUS-94189 | |
| Official U.S. PlayStation Magazine Demo Disc 02 | PSX | | | | SCUS-94198 | |
| Official U.S. PlayStation Magazine Demo Disc 03 | PSX | | | | SCUS-94210 | |
| Official U.S. PlayStation Magazine Demo Disc 04 | PSX | | | | SCUS-94211 | |
| Official U.S. PlayStation Magazine Demo Disc 05 | PSX | | | | SCUS-94212 | |
| Official U.S. PlayStation Magazine Demo Disc 06 | PSX | | | | SCUS-94213 | |
| Official U.S. PlayStation Magazine Demo Disc 07 | PSX | | | | SCUS-94214 | |
| Official U.S. PlayStation Magazine Demo Disc 08 | PSX | | | | SCUS-94215 | |
| Official U.S. PlayStation Magazine Demo Disc 09 | PSX | | | | SCUS-94216 | |
| Official U.S. PlayStation Magazine Demo Disc 10 | PSX | | | | SCUS-94217 | |
| Official U.S. PlayStation Magazine Demo Disc 11 | PSX | | | | SCUS-94218 | |
| Official U.S. PlayStation Magazine Demo Disc 12 | PSX | | | | SCUS-94219 | |
| Official U.S. PlayStation Magazine Demo Disc 13 | PSX | | | | SCUS-94275 | |
| Official U.S. PlayStation Magazine Demo Disc 14 | PSX | | | | SCUS-94276 | |
| Official U.S. PlayStation Magazine Demo Disc 15 | PSX | | | | SCUS-94277 | |
| Official U.S. PlayStation Magazine Demo Disc 16 | PSX | | | | SCUS-94278 | |
| Official U.S. PlayStation Magazine Demo Disc 17 | PSX | | | | SCUS-94279 | |
| Official U.S. PlayStation Magazine Demo Disc 18 | PSX | | | | SCUS-94280 | |
| Official U.S. PlayStation Magazine Demo Disc 19 | PSX | | | | SCUS-94281 | |
| Official U.S. PlayStation Magazine Demo Disc 20 | PSX | | | | SCUS-94282 | |
| Official U.S. PlayStation Magazine Demo Disc 21 | PSX | | | | SCUS-94429 | |
| Official U.S. PlayStation Magazine Demo Disc 22 | PSX | | | | SCUS-94430 | |
| Official U.S. PlayStation Magazine Demo Disc 23 | PSX | | | | SCUS-94431 | |
| Official U.S. PlayStation Magazine Demo Disc 24 | PSX | | | | SCUS-94432 | |
| Official U.S. PlayStation Magazine Demo Disc 25 | PSX | | | | SCUS-94433 | |
| Official U.S. PlayStation Magazine Demo Disc 26 | PSX | | | | SCUS-94434 | |
| Official U.S. PlayStation Magazine Demo Disc 27 | PSX | | | | SCUS-94435 | |
| Official U.S. PlayStation Magazine Demo Disc 28 | PSX | | | | SCUS-94436 | |
| Official U.S. PlayStation Magazine Demo Disc 29 | PSX | | | | SCUS-94437 | |
| Official U.S. PlayStation Magazine Demo Disc 30 | PSX | | | | SCUS-94438 | |
| Official U.S. PlayStation Magazine Demo Disc 31 | PSX | | | | SCUS-94499 | |
| Official U.S. PlayStation Magazine Demo Disc 32 | PSX | | | | SCUS-94583 | |
| Official U.S. PlayStation Magazine Demo Disc 33 | PSX | | | | SCUS-94591 | |
| Official U.S. PlayStation Magazine Demo Disc 34 | PSX | | | | SCUS-94593 | |
| Official U.S. PlayStation Magazine Demo Disc 35 | PSX | | | | SCUS-94596 | |
| Official U.S. PlayStation Magazine Demo Disc 36 | PSX | | | | SCUS-94599 | |
| Official U.S. PlayStation Magazine Demo Disc 37 | PSX | | | | SCUS-94614 | |
| Official U.S. PlayStation Magazine Demo Disc 38 | PSX | | | | SCUS-94617 | |
| Official U.S. PlayStation Magazine Demo Disc 39 | PSX | | | | SCUS-94622 | |
| Official U.S. PlayStation Magazine Demo Disc 40 | PSX | | | | SCUS-94628 | |
| Official U.S. PlayStation Magazine Demo Disc 41 | PSX | | | | SCUS-94630 | |
| Official U.S. PlayStation Magazine Demo Disc 42 | PSX | | | | SCUS-94631 | |
| Official U.S. PlayStation Magazine Demo Disc 43 | PSX | | | | SCUS-94634 | |
| Official U.S. PlayStation Magazine Demo Disc 43 | PSX | EDC | | | SCUS-94634 | |
| Official U.S. PlayStation Magazine Demo Disc 44 | PSX | | | | SCUS-94637 | |
| Official U.S. PlayStation Magazine Demo Disc 45 | PSX | | | | SCUS-94645 | |
| Official U.S. PlayStation Magazine Demo Disc 46 | PSX | | | | SCUS-94649 | |
| Official U.S. PlayStation Magazine Demo Disc 47 | PSX | | | | SCUS-94652 | |
| Official U.S. PlayStation Magazine Demo Disc 48 | PSX | | | | SCUS-94655 | |
| Official U.S. PlayStation Magazine Demo Disc 50 | PSX | | | | SCUS-94658 | |
| Official U.S. PlayStation Magazine Demo Disc 52 | PSX | | | | SCUS-94662 | |
| Official U.S. PlayStation Magazine Demo Disc 54 | PSX | | | | SCUS-94664 | |
| Ogre Battle: Limited Edition | PSX | | Original | | SLUS-00467 | |
| Ohio Distinctive Software Vol. I | PC | | | | | |
| Oil Tycoon | PC | 1.01 | Original | | | |
| Okage: Shadow King | PS2 | 1.01 | Original | | SCUS 97129 | |
| Olympic Soccer | PSX | | Original | | SLUS-00156 | |
| Olympic Summer Games | PSX | | Original | | SLUS-00148 | |
| Olympic Summer Games | 3DO | | Original | | FZ-SW0012 | |
| Omar Sharif Bridge | PC | 1.0 | Original | | | |
| Omega Boost | PSX | | Original | | SCUS-94449 | |
| 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 | PSX | | Original | | SLUS-00469 | |
| One Piece Mansion | PSX | | Original | | SLUS-01406 | |
| One Unit Whole Blood | PC | 1.21 | Original | | 04-16459CD1 | |
| Oni | PC | 1.0 | Original | | | |
| Oni | PS2 | 1.20 | Original | | SLUS-20064 | |
| Online Start-Up Disc 4.0 | PS2 | 1.00 | | | SCUS-97357 | |
| Online Start-Up Disc 4.0: Broadband Only | PS2 | 1.02 | Bundled with PS2 | | PBPX 95248 … | |
| Online Start-Up Disc v3.0 | PS2 | 1.01 | | | PBPX-95242 | |
| Online Start-Up Disc v3.0 | PS2 | 1.01 | | | SCUS 97425 | |
| Online Start-Up Disc v3.5: Broadband Only | PS2 | 1.00 | Original | | PBPX 95247 | |
| OnSide Soccer | 3DO | | Unlicensed (oldergames, Good Deal Games Double Header! Two Game Set) | | | |
| Operation | PC | | General Mills | | AM801R5 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDUS00 | |
| Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original | | MOFUCDUS00 | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDUS00 | |
| 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 Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.0 | Original | | OTA744AE-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 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 | 1.0 | Original | | 380859-CD | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.1 | Rerelease, Southwestern School Set | | 380859B-CD | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 381032-CD/i401ha | |
| Oregon Trail II | PC | 1.31 | Rerelease | | #HCD744AE-CD | |
| Oregon Trail II: 25th Anniversary Limited Edition | PC | 1.3 | Original, SoftKey | | #OTR744AE-CD | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Original Links | PC | | Solid Gold Edition | | | |
| Out of This World | 3DO | | Original | | | |
| Out of This World | 3DO | RE | 3DO Maniac Pack | | | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| 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 2) | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outpost | PC | | Original | | S725430 | |
| Outpost | PC | 1.5 | Rerelease, Sierra Originals | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 1) | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 2) | PC | | Original | | | |
| OverBlood | PSX | | Original | | SLUS-00464 | |
| Olympic Soccer | 3DO | | Original | | FZ-SW0011 | |
| Omikron: The Nomad Soul | DC | 1.001 | Original | | T-36807N | |