O
- Opeth
- Orphaned Land
- Osbourne Ozzy
- OOMPH
- Output
- Onmyo-Za
- Oasis
- Overkill
- Orishas
- Operation Ivy
- Offspring The
- Orff Carl
- Onose Jun
- Orbison Roy
- Octavia
- Ona
- Orgy
- Osborne Joan
- Ozz82
- Oldfield Mike
- Overload
- Obituary
- Ondes Negatives Les
- Omega
- One Dollar Short
- Our Lady Peace
- Osny
- Otep
- Orcblood
- Otro Yo El
- Old Mans Child
- Obus
- Obliveon
- Orange Seabones
- Oversoul
- Offspring
- Osker
- Overflow
- Old Dead Tree The
- October Falls
- Ossian
- Otherwise
- Obsidio
- Ocean Colour Scene
- Otm Shank Jazz Quintet The
- Obrint Pas
- Olsson Sven
- Oficina G3
- Oginskiy
- Opiosos Os
- Orchestral Manoeuvres In The Dark Omd
- Ostria Marcelo
- Obligation Or Reputation
- Oleander
- Osvajaci
- Ozric Tentacles
- Obispo Pascal
- Oxidus
- Outlaw Torn The
- Office Of Strategic Influence
- Oleyire
- Osmi Putnik
- Old Man Willow
- Oreja De Van Gogh La
- Ogres De Barback Les
- Offenbach Jacques
- October Thorns