Region | Title | System | Version | Edition | Languages | Serial | Status |
| 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 | WII | | 40th Anniversary Edition | | RVL-SORE-USA-B0 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| Oretachi Geesen Zoku: Akumajou Dracula オレたちゲーセン族 悪魔城ドラキュラ | PS2 | 1.01 | Original | | SLPM 62729 | |
| Oretachi Geesen Zoku: Karate-dou オレたちゲーセン族 空手道 | PS2 | 1.01 | Original | | SLPM 62628 | |
| Oretachi Geesen Zoku: Nekketsu Kouha Kunio-kun オレたちゲーセン族 熱血硬派くにおくん | PS2 | 1.01 | Original | | SLPM 62706 | |
| Oretachi Geesen Zoku: Pooyan オレたちゲーセン族 プーヤン | PS2 | 1.01 | Original | | SLPM 62731 | |
| Oretachi Geesen Zoku: Super Volleyball オレたちゲーセン族 スーパーバレーボール | PS2 | 1.04 | Original | | SLPM 62660 | |
| Oretachi Geesen Zoku: Time Pilot オレたちゲーセン族 タイムパイロット | PS2 | 1.01 | Original | | SLPM 62644 | |
| Oretachi ni Tsubasa wa Nai 俺たちに翼はない | PS3 | 01.01 | Original | | BLJM 61018 | |
| 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 | |
| Ori and the Blind Forest: Definitive Edition | PC | 5.3.2.9582331 | Limited Edition | | | |
| The Original Links | PC | | Solid Gold Edition | | | |
| Oro e Gloria: La Strada per El Dorado | PSX | | Original | | SLES-03186 | |
| Oshidashi Zintrick ~ ZinTricK 押し出しジントリック | NGCD | | Original | | ADCD-104 | |
| Oshigoto-shiki Jinsei Game: Mezase Shokugyou King お仕事式人生ゲーム めざせ職業王 | PSX | | Original, The Best Takaramono | | SLPM 87316 … | |
| Othello | CDI | | Original | | 810 0163 | |
| Othello | PC | | Original | | | |
| Othello World II: Yume to Michi e no Chousen オセロワールドII 夢と未知への挑戦 | PSX | | Original, Fukkokuban | | SLPS 00136 … | |
| Other Life Azure Dreams アザーライフ アザードリームス | PSX | | Original | | SLPM 86047 | |
| Oto to E no Deru Eigo Jisho No. 2: English in Dream 音と絵の出る英語辞書 No.2 「English in Dream」 | FMT | | Original | | HMB-129 | |
| Oto to E no Deru Eigo Jisho No. 3: Nandemo Illust Eigo Jiten 音と絵の出る英語辞書 No.3 「なんでもいらすとえいごじてん」 | FMT | | Original | | HMB-131 | |
| Oto to E no Deru Eigo Jisho No. 4: Nandemo Illust Eigo Jiten Part 2 音と絵の出る英語辞書 No.4 「なんでもいらすとえいごじてん Part 2」 | FMT | | Original | | HMB-170 | |
| Otogi O・TO・GI ~御伽~ | XBOX | | Original | | FS-002 | |
| Otogi Story: Tenshi no Shippo おとぎストーリー ~天使のしっぽ~ | PSX | | Original | | SLPS 03531 | |
| Otogi: Hyakki Toubatsu Emaki O・TO・GI ~百鬼討伐絵巻~ | XBOX | | Special Pack | | FS-004 | |
| Otogi: Myth of Demons | XBOX | | Special Pack | | FS-002 | |
| Otogi: Myth of Demons | XBOX | | Original | | FS-002 | |
| Otome-teki Koi Kakumei: Love Revo!! 乙女的恋革命★ラブレボ!! | PS2 | 1.03 | Original, Love Revo Box | | SLPM 66238 … | |
| Otorva v shkole Оторва в школе | PC | | Original | | | |
| Otostaz 蓋蓋樂 | PS2 | 1.00 | Original | | SCPS 55023 | |
| Otostaz オトスタツ | PS2 | 1.00 | Original | | SCPS 11024 | |
| Otostaz オトスタツ | PS2 | 1.00 | Taikenban | | PAPX 90228 | |
| Otostaz オトスタツ | PS2 | 1.00 | Taikenban | | SCPS 11020 | |
| Otverzhennye: Tajna temnoj rasy (Disc 1) Отверженные: Тайна темной расы | PC | | 1C: Igrushki | | SNOW OT21 0110 IR | |
| Oukyuu no Hihou Tension 王宮の秘宝 テンション | PSX | | Original, VAP Best Thanks 1800 | | SLPS 00438 … | |
| Oumagatoki 逢魔が時 | PSX | | Original, PSone Books | | SLPS 03235 … | |
| Oumagatoki 逢魔が時 プレミアム"FAN"ディスク | PSX | | Premium Fan Disc | | SLPM 80623 | |
| Ouran Koukou Host Club 桜蘭高校ホスト部 | PS2 | 1.01 | Genteiban | | SLPM 66737 | |
| Out of This World | 3DO | | Original | | | |
| Out of This World | 3DO | RE | 3DO Maniac Pack | | | |
| Outcast | PC | | Original | | | |
| Outcast (Disc 1) | PC | | Original | | OUTCAPC52G/A1 | |
| Outcast (Disc 2) | PC | | Original | | OUTCAPC52G/A2 | |
| Outcast (Disc 1) | PC | | Covermount | | | |
| Outcast (Disc 2) | PC | | Covermount | | | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| The Outfit | XBOX360 | | Original | | TQ-2002 | |
| Outlaw Golf | PS2 | 1.01 | Original | | SLES-51926 | |
| Outlaw Golf 2 | XBOX | | Original | | TT-023 | |
| Outlaw Golf 2 | PS2 | 1.01 | Original | | SLES-52965 | |
| Outlaw Golf: Holiday Golf | XBOX | | Original | | SS-005 | |
| Outlaw Tennis | PS2 | 1.01 | Original | | SLES-53490 | |
| Outlaw Volleyball | PS2 | 1.01 | Original | | SLES-52259 | |
| Outlaw Volleyball Remixed | PS2 | 1.01 | Original | | SLES-53138 … | |
| 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 2) | PC | 1.0 | Original | | | |
| Outlaws (Disco 1) | PC | 2.0 | Collezione CD-Rom by C.T.O. | | LUC628 | |
| Outlaws (Disco 2) | PC | 2.0 | Collezione CD-Rom by C.T.O. | | LUC628 | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Original | | 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 | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost | PC | | Original | | S725430 | |
| Outpost | PC | 1.5 | Rerelease, Sierra Originals | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Outpost 2: Geteilte Bestimmung | PC | 1.0 | Original | | S0011248 | |
| OutRun 2 SP アウトラン2 スペシャルツアーズ | PS2 | 1.03 | Shokai Genteiban | | SLPM 66628 | |
| OutRun 2006: Coast 2 Coast | PC | | Gamer's Choice | | THQ70690 | |
| OutRun 2006: Coast 2 Coast | PC | 1.0 | Original | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast | PSP | 1.01 | Original, Platinum: The Best of PSP | | ULES-00262 | |
| OutRun 2006: Coast 2 Coast | PS2 | 1.02 | Original | | SLES-53998 | |
| OutRun 2006: Coast 2 Coast | PC | 1.00.0000 | Serie Maxima II | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast | PC | | eXtra Klasyka XK HIT | | TS OCC PL | |
| OutRun 2006: Coast 2 Coast | PS2 | 1.01 | Original | | SLUS 21274 | |
| OutRun 2006: Coast 2 Coast | XBOX | | Original | | SE-136 | |
| Outward | PC | | Day One Edition | | 1024669LAINT, 103699 | |
| 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 Drivin' DX: Rally Edition オーバードライビンDX ラリーエディション | PSX | | Hibaihin | | SLPM 80032 | |
| Over G Fighters | XBOX360 | | Original | | TI-2001 | |
| Overwatch | PC | | Game of the Year Edition, Legendary Edition | | 73052010US, S7302210 | |
| Overwatch | PC | | Origins Edition | | | |
| Oyaji Hunter Mahjong おやじハンター・マージャン | 3DO | | Original, Sample | | IMP-SF0703 | |