| title | developer | year | game type | | pop. |
|---|
| O.D.T. | Psygnosis | 1998 | PS | action/reflex adventure | image | subject | label | |
| Oasis Road | Idea Factory | 1999 | PS | | image | | | |
| Ochan no Oekaki Logic | Sunsoft | 1995 | PS | | | | label | |
| Ochan no Oekaki Logic 2 | Sunsoft | 1996 | PS | | | | label | |
| Ochan no Oekaki Logic 3 | Sunsoft | 2001 | PS | | image | | label | |
| Ochanoma Battle | Hori | 2000 | PS | | image | | | |
| Oda Nobunaga Den | Koei | 1998 | PS | role-play | image | | | |
| Oddworld: Abe's Exoddus | Oddworld Inhabitants | 1998 | PS | action/reflex platformer adventure Humorous | image | subject | label | |
| Oddworld: Abe's Oddysee | Oddworld Inhabitants | 1997 | PS | platformer Humorous | image | subject | label | |
| Odo Odo Oddity | IDC | 1997 | PS | action/reflex shooter | image | subject | | |
| Oekaki Puzzle | Success | 1999 | PS | | image | | label | |
| Oekaki Puzzle 2 | Success | 2000 | PS | | image | | | |
| Oekaki Puzzle 3 | Success | 2000 | PS | | image | | label | |
| Oekaki Puzzle 4 | Success | 2000 | PS | | | | | |
| Oekaki Puzzle 5 | Success | 2001 | PS | | | | | |
| Off-World Interceptor Extreme | Crystal Dynamics | 1995 | PS | racing/driving | image | subject | | |
| Ogre Battle | Quest | 1996 | PS | strategy role-play Fantasy | image | subject | label | |
| Oh No! | Asmik | 2000 | PS | action/reflex | image | | | |
| Oha Star Dance Dance Revolution | KCET | 2000 | PS | | image | | label | |
| Oja Majo Doremi Dokkan! Nijiiro Paradise | Bandai | 2002 | PS | board game | image | | label | |
| Ojousama Express | Media Works | 1998 | PS | adventure | image | | | |
| Ojyousama Express | MediaWorks | 1998 | PS | | | | | |
| Okappari-Oh | Naxact Soft | 1998 | PS | | image | | | |
| Olympia Takasago: Virtua Pachi-Slot 3 | Map Japan | 1998 | PS | casino/cards | image | | label | |
| Olympia Yamasa: Virtua Pachi-Slot 2 | Map Japan | 1997 | PS | | | | label | |
| Olympic Games: Atlanta '96 | Silicon Dreams Studio | 1996 | PS | sport | image | subject | label | |
| Olympic Soccer: Atlanta '96 | US Gold;Eidos;Coconuts Japan | 1996 | PS | sport | image | subject | label | |
| Omega Assault | ? | ? | PS | | | | | |
| Omega Boost | Polyphony Digital | 1999 | PS | shooter simulation Science Fiction | image | subject | label | |
| Omiai Commando | Enix | 2000 | PS | action/reflex | image | | | |
| Omikron | Quantic Dream | 2000 | PS | action/reflex beat 'em up shooter adventure Fantasy | | | label | |
| Omise de Tensyu | Technosoft | 1999 | PS | role-play | image | | | |
| Omizu no Kadou | Pony Canyon | 2000 | PS | | image | | | |
| One | ASC Games | 1997 | PS | adventure | image | subject | label | |
| One on One | Jorudan | 1998 | PS | sport | image | subject | label | |
| One Piece Grand Battle 2 | Ganbarion | 2002 | PS | beat 'em up Manga | image | | label | |
| One Piece Grand Battle! | Bandai | 2001 | PS | beat 'em up fighting Manga | image | subject | label | |
| One Piece Mansion | Capcom | 2001 | PS | simulation Manga | image | subject | label | |
| One Piece: Ocean's Dream | Bandai | 2003 | PS | role-play Manga | image | subject | label | |
| One Piece: Tobidase Kaizokudan! | Bandai | 2001 | PS | role-play Manga | image | | label | |
| One Two Smash: Tanoshii Tennis | Hect | 2000 | PS | | image | | | |
| One: Kagayaku Kisetsu e | Tactics | 1999 | PS | Manga | image | subject | | |
| Ongaku Tsukuru: Kanade-Ru 2 | Ascii | 1998 | PS | | | | | |
| Oni Rei: Fukkatsu | Pandora Box | 2001 | PS | role-play Fantasy | image | | | |
| Ooedo Huusui Ingaritsu Hanabi 2 | Magical Company | 2000 | PS | board game | image | | | |
| Option Tuning Car Battle | MTO | 1998 | PS | | image | | | |
| Option Tuning Car Battle 2 | Jaleco | 1999 | PS | | | | | |
| Option Tuning Car Battle Spec-R | MTO;Success | 2000 | PS | racing/driving | image | | | |
| Oracle no Houseki | Sunsoft | 1996 | PS | | image | | | |
| Ore no Ryouri | Argent;Japan Studio | 1999 | PS | action/reflex | image | subject | label | |
| Ore no Shikabane o Koete Yuke | Alfa System;Japan Studio | 1999 | PS | role-play | image | | label | |
| Osaka | King Records | 1999 | PS | | image | | | |
| Osaka Naniwa Matenrow | Kid Genius | 1999 | PS | | image | | | |
| Oshi no Mu | Astec 21 | 2000 | PS | | | | | |
| Oshigoto Nojinsei Game | Takara | 2000 | PS | | | | | |
| Otenami Haiken | Success | 2001 | PS | | | | | |
| Otenki Kororin | Takumi | 2002 | PS | puzzle | image | | | |
| Othello World 2: Yumeto Michi he no Chousen | Tsukuda Original | 1995 | PS | | | | label | |
| Otona no Asobi | Nichibutsu | 1999 | PS | casino/cards | image | subject | label | |
| Ouji-sama LV1 | Kid Genius | 2002 | PS | | image | | | |
| Ouji-sama LV1.5 | Kid Genius | 2003 | PS | | image | | | |
| Oukyuu no Hihou: Tenshon | Vap | 1996 | PS | | image | | | |
| Oumagatoki | Victor Interactive | 2001 | PS | Horror | | | | |
| Oumagatoki 2 | Victor Interactive | 2001 | PS | adventure Horror | image | subject | label | |
| Our Graduation | Kid Genius | 2000 | PS | board game | image | | label | |
| Out Live: Be Elminate Yesterday | Sunsoft | 1997 | PS | | | | | |
| Over Drivin' Skyline Memorial | Electronic Arts;Victor | 1997 | PS | | | | | |
| Over My Body | Sony | 1999 | PS | role-play | image | | | |
| OverBlood | Riverhill Soft | 1996 | PS | action/reflex adventure Horror | image | subject | label | |
| OverBlood 2 | Riverhill Soft | 1998 | PS | action/reflex adventure Horror | image | | label | |
| Overboard! | Psygnosis | 1997 | PS | action/reflex strategy | image | | label | |
| Oyaji no Jikan: Nechan, Hanafuda de Shoubu Ya | Visit | 2000 | PS | | image | | label | |
| Oyaji no Jikan: Nechan, Mahjong de Shoubu Ya | Visit | 2000 | PS | | image | | | |
| Oyaji no Jikan: Nechan, Tsuri Iku De! | Visit | 2000 | PS | sport | image | | | |
