| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | Oblivious Garden: Carmina Burana (Disc 2) (Music Disc) | PC | | Standard Edition |  | |  |
 | ODN Palm Power Pack | PALM | | Original | | | |
| Official Disc 2003 | PS2 | 1.01 | Taikenban |  | PAPX 90507 | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| Oh!PC 1998-nen 10-gatsu-gou Tokubetsu Furoku CD-ROM
Ｏｈ！ＰＣ １９９８年 １０月号 特別付録ＣＤ－ＲＯＭ | PC | | | | OHPC-9810 | |
| Oh!PC 1998-nen 11-gatsu-gou Tokubetsu Furoku CD-ROM
Ｏｈ！ＰＣ １９９８年 １１月号 特別付録ＣＤ－ＲＯＭ | PC | | | | OHPC-9811 | |
| Oh!PC 1998-nen 8-gatsu-gou Tokubetsu Furoku CD-ROM
Ｏｈ！ＰＣ １９９８年 ８月号 特別付録ＣＤ－ＲＯＭ | PC | | | | OHPC-9808 | |
| Oh!PC 1998-nen 9-gatsu-gou Tokubetsu Furoku CD-ROM
Ｏｈ！ＰＣ １９９８年 ９月号 特別付録ＣＤーＲＯＭ | PC | | | | OHPC-9809 | |
| Oh!X 1998 Spring Special CD-ROM (Part 1) | X68K | | | | | |
| Oh!X 1998 Spring Special CD-ROM (Part 2) (Sampler Disc) | X68K | | | | | |
| Oh!X 1999 Spring Special CD-ROM (Part 1) | X68K | | | | | |
| Oh!X 1999 Spring Special CD-ROM (Part 2) (Sampler Disc) | X68K | | | | | |
| Oh!X 1999 Summer Special CD-ROM | X68K | | | | | |
| Oh!X 2000 Spring Special CD-ROM (Part 1) | X68K | | | | | |
| Oh!X 2000 Spring Special CD-ROM (Part 2) | X68K | | | | | |
| Oh!X 2001 Spring Special CD-ROM | X68K | | | | | |
| Oilman
オイルマン | 3DO | | Hibaihin | | OIL-9610 | |
| Olympia, Yamasa: Virtua Pachi-Slot II: Jissen! Bishoujo Kouryakuhou
オリンピア・山佐 バーチャパチスロⅡ ～実戦！美少女攻略法～ | PSX | | Original | | SLPS 00714 | |
| One-derful Theater
ＯＮＥだふるシアター | X68K | | | | | |
| Operation Wolf
オペレーション・ウルフ | FMT | 1.00 | Ving Vol. 3 | | HMB-126 | |
| The Orange Box | XBOX360 | | Original | | EA-2063 | |
 | The Orange Box (Disc 1)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original |          | TTE0193 | |
| The Orange Box (Disc 2)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original | | TTE0193 | |
