- Ornella D'Urbano
- Ohm Square
- Oathbreaker
- Only Hope
- Officium Triste
- OverDoz.
- O.U.O
- Os Originais Do Samba
- Opus Sanctus
- 웁스나이스 (OopsNice)
- Original Broadway Cast of On Your Feet
- Owen Ni
- 원케이스 (One.Case)
- Orchestra da Camera Fiorentina
- Oliveray
- Olivier Giacomotto
- Oba Oba Samba House
- On-The-Go
- Ola Kvernberg
- Ocean Girls
- OLD
- Omar Bashir
- Oceana组合
- O.C. Supertones
- Ozbi
- Oto Pestner
- Out Of Grace
- Optimus Gryme
- Oliva
- Orchestra of the Accademia di Santa Cecilia
- Oleg Poliakov
- Orchestre Paul Kuentz
- Oak Shine
- Oxilite
- Owen Pallett
- On Our Own
- OBE
- Orbit
- OMD (夜半行军乐团)
- Oro Solido
- オワリカラ (OWARIKARA)
- Olaf Berger
- OSKIDO
- Oscar Yestera
- OLEDICKFOGGY (オールディックフォギー)
- Omnicron
- Oba Frank Lords
- Organized Konfusion
- O'Jays
- O Tchan
- Outside
- Original Cast Vienna
- Oxoon
- 온더로드 (ON THE ROAD)
- Omvr
- Ondine
- Old Brick Warehouse
- Ostzonensuppenwürfelmachenkrebs
- Oliver Englafjord
- Orquesta de Música Valentín Alegría
