Osu
- Moero! Nekketsu Rhythm Damashii Osu! Tatakae! Ouendan 2
- Ohio State University
- Ohio State University Airport
- Okayama Shoka University
- Oklahoma State University
- Old Salt Union
- Operation Straight Up
- Oregon State University
- Osu Castle
- Osu caste system
- Osu! Tatakae! Ouendan
- Osu! Tatakae! Ouendan (series)
- Osu, Accra
- Ottawa South United
- Ozu (disambiguation)
- Ursulines
- Ōsu