- Orquesta Típica de Buenos Aires
- Ongakushitsu
- Oceansize
- Orrin Evans
- Orquesta Romanticos de Cuba
- OCEANLANE
- Ocean Shiver
- Ototom
- Ozzy
- Olga Bell
- Oxyd
- Orquesta Bans
- Orquesta Lírica Bellaterra
- 오사마리 (OSA)
- Otherkin
- odaxelagnia
- O.P.2
- Orchestra Andrea e Lorena
- Other2Sides
- Oliver Gunning
- OX7GEN
- Oranger
- 欧阳日华
- Open Mike Eagle
- Overtures
- Old Man River
- Osborne Brothers
- Overcast
- Obtained Enslavement
- Orquesta de Pulso y Pua Salmantina
- É O Tchan
- Otayo Dubb
- Ofra Harnoy
- Os Tubarões
- Orientation
- 오리엔탈 루시 (Oriental Lucy)
- 오곤 (O!Gon)
- 偶想Drop
- 欧阳静
- Olivier Depardon
- Ocean Beach Waves
- Original Broadway Cast of Avenue Q
- Opera To Relax
- Omar Kamal
- Oz Noy
- Orquesta de Lubov
- Orician
- Oiseaux-Tempête
- Ony
- Olidena
- On Broken Wings
- Ollantay
- OLI
- Orchestra Mikrokosmos
- Okkyung Lee
- Orquesta Baladisima
- Olympia
- Oh,Sleeper
- Orquesta De Chino Flores
- Orchester Anthony Ventura
