- One Republic
- OneRepublic
- Onslaught
- Onyx
- Oomph!
- Opera Ix
- Operation Ivy
- Opeth
- Opm
- Orange Range
- Orbital
- Orchestral Manoeuvres In The Dark
- Orchid
- Ordo Equilibrio
- Ordo Rosarius Equilibrio
- Orgy
- Orianthi
- Origa
- Origin
- Orion
- Orishas
- Orphaned Land
- Orson
- Osbourne Ozzy
- Ost
- Otep
- Otis Redding
- Ott
- Otto Dix
- Our Lady Peace
- Our Last Night
- Ours
- Out of Eden
- Outasight
- Outcast
- Outfield
- Outkast
- Outlandish
- Outlawz
- Ov7
- Over The Rhine
- Overkill
- Owl City
- OxxxyMiron
- Oxymoron
- OZ
- Ozma
- Ozzy Osbourn
- Ozzy Osbourne
- Oliver Heldens X Becky Hill