| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | Ore! Tomba
オレっ！トンバ | PSX | | Taikenban |  | SLPM 80165 | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| Ore! Tomba
オレっ！トンバ | PSX | | Original | | SLPS 01144 | |
 | 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 | 1.0 | Original | | | |
| 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: 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 | |
| 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 | |
| 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 | |
 | Origami | CDI | | Original |    | 810 0041 | |
| The Original Links | PC | | Solid Gold Edition | | | |
 | Die Original Moorhuhn Jagd | PC | | Best of Moorhuhn | | | |
 | Original War (Disc 1) | PC | | Original, Gamer Collector | | | |
| Original War (Disc 2) | PC | | Original, Gamer Collector | | | |
| Orion Burger | PC | | Gold Games 2 (CD 11) | | SPI 046 | |
| Orion's Puzzle Collection | DC | 1.000 | Unlicensed | | | |
 | Oro e Gloria: La Strada per El Dorado | PSX | | Original |  | SLES-03186 | |
| Oscar | PC | | Original | | | |
| Oscar | PC | | Jackson Libri | | | |
| 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 | | SCPS 45126 … | |
| 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 Story: Tenshi no Shippo
おとぎストーリー ～天使のしっぽ～ | PSX | | Original | | SLPS 03531 | |
 | Otorva v shkole
Оторва в школе | PC | | Original |  | | |
| 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 | | PAPX 90226 | |
| 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 | |
| Oudou Yuusha
王道勇者 | PC | | Original | | ALS-0029 | |
| Ougon Kishi Garo
黄金騎士 牙狼 | PS2 | 1.01 | Original | | SLPS 20463 | |
| Oukoku no Grand Chef
王国のグランシェフ | 3DO | | Original | | FZ-SJ4252 | |
| 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 | PSX | | Premium Fan Disc | | SLPM 80623 | |
| Out of This World | 3DO | | Original | | | |
| Out of This World | 3DO | RE | 3DO Maniac Pack | | | |
| 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 | | Play the Games Vol. 3 | | | |
| Outcast (Disc 1) | PC | | Covermount | | | |
| Outcast (Disc 2) | PC | | Covermount | | | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| 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 1) | PC | | M6 Multimedia | | M6IMM6 | |
| Outlaws (Disc 2) | PC | | Original | | | |
| Outlaws (Disc 2) | PC | | M6 Multimedia | | M6IMM6 | |
| 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 | 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 | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
 | Outlaws (Disc 1)
アウトロー | PC | 1.0 Build 3 | Original | | 9511830 | |
| Outlaws (Disc 2)
アウトロー | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws: Die Gesetzlosen (Disc 1) | PC | 1.1 | Rerelease | | | |
| Outlaws: Die Gesetzlosen (Disc 2) | PC | 1.1.1 | Rerelease | | | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost | PC | | Original | | S725430 | |
| Outpost | PC | 1.5 | Rerelease, SierraOriginals | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Outpost 2: Geteilte Bestimmung | PC | 1.0 | Original | | S0011248 | |
| OutRun 2006: Coast 2 Coast (Disc 1) | PC | | Original |  | | |
| OutRun 2006: Coast 2 Coast (Disc 2) | PC | | Original | | | |
| Outtrigger | DC | 1.001 | Original, Sample | | 952-0162-50, MK-51102-50 | |
| Outtrigger
アウトトリガー | DC | 1.008 | Original | | HDR-0118 | |
| 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 10 Tetrix Games | PC | | Original | | | |
