Games
- Okamiden: Chiisaki Taiyo
- Okhlos
- Okunoka
- Old World
- OlliOlli
- OlliOlli World
- OlliOlli2: Welcome to Olliwood
- Omega Quintet
- Omno
- One Piece Odyssey
- One Piece: Grand Cruise
- One Piece: Unlimited Cruise SP
- One Punch Man: A Hero Nobody Knows
- One Step from Eden
- Onimusha 2
- Onimusha 3
- Onimusha 3: Demon Siege
- Onimusha Warlords
- Oninaki
- Onrush
- Ooblets
- Open Roads
- Operation Flashpoint: Dragon Rising
- Operation Flashpoint: Red River
- OPUS: Echo Of Starsong