- O-1 -- Obliteration
- Obliterator -- OD
- OD Ball -- Off the Turnpike
- Off the Wagon -- Oi! The Arrase
- Oi Va Voi -- Old Bay Céilí Band
- Old Bear Mountain -- Olin Nejezchleba & ETC...
- Olin Smith -- Olivier Lalloutte
- Olivier Latry -- Omar Souleyman
- Omar Souleyman Band -- Once Waz Nice
- once11 -- One World/One People International Women's Choi
- One World (Reggae) -- Open Air
- Open-Air Museum -- Orange & Atlas
- Orange Avenue -- Orchestra Filharmonica Della Scala
- Orchestra Flamboyan -- Orchestre National de l'Opéra de Monte-Carlo
- Orchestre National de l'Opéra de Monte-Carlo [Orchestra] -- Oriental Spas
- Oriental Star -- Orlando Nnez
- Orlando N?nez -- Orquesta Martin DeLaRosa
- Orquesta Matamoros -- O.S. Grant & The Downbeats
- Os Havaianos -- Osho Musicians
- Osho School Of Music And Celebration -- Otis
- Otis -- Out In Worship
- Out Like Wolves -- Overlord
- Overlord -- Ozzy Osbourne