| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | Oracle no Houseki: Jewels of the Oracle
オラクルの宝石 | SS | 1.004 | Original |     | T-1511G | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| Ooedo Renaissance
大江戸ルネッサンス | SS | 1.001 | Original | | T-9104G | |
| Omakase! Savers
おまかせ！退魔業 | SS | 1.002 | Original | | GS-9030 | |
 | Olympic Soccer | SS | 2.000 | Original |   | T-7904H-09, T-7904H-50 | |
| Ojousama o Nerae!!
お嬢様を狙え！！ | SS | 1.002 | Original | | T-38101G | |
| Ojousama Express (Disc 2)
お嬢様特急 | SS | 1.005 | Original | | T-27803G | |
| Ojousama Express (Disc 1)
お嬢様特急 | SS | 1.005 | Original | | T-27803G | |
| Oh-chan no Oekaki Logic
おーちゃんのお絵かきロジック | SS | 1.005 | Original | | T-1508G | |
| Ochigee Designer Tsukutte Pon!
落ちゲー・デザイナー 作ってポン！ | SS | 1.090 | Original | | T-9108G | |
| Ousama Game (Disc 2) (Momo Disc)
王様げーむ | SS | 1.001 | Original | | T-21904G |  |
| Ousama Game (Disc 1) (Ichigo Disc)
王様げーむ | SS | 1.001 | Original | | T-21904G | |
 | Olympic Soccer | SS | 2.000 | Original | | T-7904H | |
| Olympic Soccer
オリンピックサッカー | SS | 1.002 | Original | | T-7304G | |
 | Olympic Soccer | SS | 2.000 | Original | | T-07904H-18 | |
| Okudera Yasuhiko no Sekai o Mezase! Soccer Kids: Nyuumon-hen
奥寺康彦の世界をめざせ! サッカー・キッズ 入門編 | SS | 1.310 | Original | | T-26001G | |
| Ojousama o Nerae!!
お嬢様を狙え！！ | SS | 1.003 | Original | | T-38101G | |
| Off-World Interceptor Extreme | SS | 1.000 | Original | | T-15908H | |
| Off-World Interceptor Extreme
オフワールド・インターセプター エクストリーム | SS | 1.000 | Ketteiban | | T-15901G | |
| Off-World Interceptor Extreme | SS | 1.000 | Original | | T-15908H-50 | |
