Groups & Artists – O
- O-Town
- O'Brien, Richard
- O'Connell, Finneas
- O'Connor, Mark
- O'Connor, Sinead
- O'Day, Anita
- O'Hagan, Jack
- O'Jays
- O'Keefe, Laurence
- O'Reilly, John
- O'Sullivan, Gilbert
- Oakey, Philip
- Oaks, Mighty
- Oasis
- Oates, John
- Obel, Agnes
- Obispo, Pascal
- OBK
- Ocean Colour Scene
- Ocean, Frank
- Ochaita, Valero And Solano
- Ocheltree, Jeff
- Odell, Tom
- Odrich, Ron
- Oerding, Johannes
- Of Monsters And Men
- Offer, Charles
- Offspring, The
- Ogdon, John
- Ohio Players
- Oimara
- Olatunji, Babatunde
- Old Dominion
- Oldfield, Mike
- Oliver, Joe "King"
- Olly The Enemy
- OMI
- Onderet, Maurice
- One Direction
- OneRepublic
- Onions, Oliver
- Ono, Yoko
- Opera Babes
- Ora, Rita
- Orange Blue
- Orbison, Roy
- Orchestral Manoeuvres in the Dark
- Oregon
- Oreja de Van Gogh, La
- Orrico, Stacie
- Orson
- Orton, Beth
- Ory, Kid
- Osborne Brothers, The
- Osborne, Gary
- Osborne, Joan
- Osbourne, Ozzy
- Osmond, Donny
- Osmond, Jimmy
- Otis, Johnny
- Otonkoski, Lauri
- Ott, Kerstin
- Outkast
- Ovaltineys, The
- Owen, Jake
- Owens Harry
- Owens-Collins, Jamie
- Owl City
- Oxford Waits
