O
- Ó Lionáird, Iarla
- O´Connor, Hazel
- O´Connor, Sinéad
- O´Jays, The
- O´Keefe, Danny
- O´Sullivan, Gilbert
- Oakenfold, Paul
- Oasis
- Obiman
- Obituary
- Oblivious
- Öcal, Burhan
- Ocean Colour Scene
- Ocean, Billy
- Octopus
- Oda, Neil
- Odetta
- Of Montreal
- Offspring, The
- Ohio Express
- Ohio Players
- Ochs, Phil
- Oi Polloi
- Oldfield, Mike
- Ole Lukkoye
- Oliver Onions
- Olivia Tremor Control
- Olomidé, Koffi
- OM
- OMD