O
- O.A.R.
- O'G3NE
- Oasis
- Oasis Ministry
- Obadiah Parker
- Oberhofer
- Ocean Colour Scene
- Ocean Wisdom
- OCEANDVST
- Ocie Elliott
- Octavio Cuadras
- Odd Girl Out
- Odds
- Odetta
- Odisseo
- Oen Kennedy
- Of Monsters and Men
- of Montreal
- Ofenbach
- Off Road Minivan
- offonoff (오프온오프)
- Offspring, The
- Ogie Alcasid
- Oh Sixteen Oh Seven
- Oh Wonder
- Ohio Players
- Ohmme
- Oi Va Voi
- Oingo Boingo
- OK Go
- ok.danke.tschüss
- Okkervil River
- oktobernatt
- Olaf Henning
- Old 97's
- Old And In The Way
- Old Crow Medicine Show
- Old Dominion
- Old Sea Brigade
- Olda Rypar
- Oldcodex
- Olga Guillot
- Olive Klug
- Olive Vox
- Oliver Anthony Music
- Oliver Dragojević
- Olivia Dean
- Olivia Ellen Lloyd
- Olivia Georgia
- Olivia Lufkin
- Olivia Newton-John
- Olivia O'Brien
- Olivia Rodrigo
- Ollie Green
- Ollie MN
- Olly Murs
- Olomana
- Olsenbanden Jr.
- Olympia
- Olympic
- Omar Naber
- OMC
- Omi
- Omnia
- Ona (US)
- Onbeskaamd
- Once Mekel
- one
- One Common
- One Direction
- One Leaf Falls
- ONE OK ROCK
- OneRepublic
- ONEW (온유)
- ONEWE
- ONI INC.
- Onirama
- Only The Poets
- Oomph!
- Opeth
- Opick
- Orange & Lemons (Philippines)
- Orchestral Manoeuvres in the Dark (OMD)
- Ordinary Time
- Organek
- Orient Pearl
- Orion Sun
- Orion the Hunter
- ORKID
- Orlando
- Orlando Hernandez
- Orphaned Land
- Orsa Lia
- Orthodox Celts
- Os Arrais
- Os Mutantes
- Osca
- Oscar and the Wolf
- Oscar Isaac
- Oscar Lang
- Oscar Maydon
- Osvajači
- Other Lives
- Otherwise
- Otis Kane
- Otis Redding
- OTR
- Otto Waalkes
- Our Lady Peace
- Our Last Night
- Ours
- Ouse
- Ouse (Iceland)
- OutKast
- Over It
- Over October
- Overcoats
- Overgrown
- Overpass
- Overserved Again
- Ovlov
- Ovni
- Owen
- Owen Pallett
- Owl City
- Owl-Moniker Athy
- Oysterband
- Ozark Henry
- Ozzy Osbourne