- Okko Kamu
- Okkultokrati
- Okky Ardila
- Okky Del Rey
- Okkyung Lee
- Oklahoma
- Oklahoma Bomb Squad
- 'Oklahoma!' Company
- Oklahoma Playboys
- Oklahoma State Wind Ensemble
- Oklahoma Swing Band
- Oklahoma Tornadoes
- Oklahomo Trio
- Oklahomos
- Okma
- Okna Tsahan Zam
- Oknard 5
- Oko 3
- Oko Jumo
- Oko Jumu
- Oko Tek
- Okoliczny Element
- Okolokolo
- Okonko
- Okoth Bosco
- Okou
- Okoumé
- Okoun Ensemble
- Okploïde
- Okr
- Okra
- Okre Boy
- Okros Folk Music Ensemble
- Oks
- Oksana
- Oksana Gerasymenko
- Oksana Herasymenko
- Oksana Lutsyshyn
- Oksana Moshinsky