| Oinker Doinkers |
| Oitavo Esquerdo |
| OJ da Juiceman |
| OJ Mariano |
| Ojai Valley Boys |
| Ojerime |
| Ojete Calor |
| Ojo |
| Ojos de Brujo |
| Ok Go |
| OK KID |
| Ok Moon |
| Ok, tyler |
| OKAMOTO'S |
| Okan Akçay |
| Okan Aktaş |
| Okan Tok |
| Okapi Guitars |
| Okasian |
| Okay Aybey |
| Okay Barış |
| Okay Kaya |
| Okay Mann |
| Okefenokee Orchestra |
| Oken |
| Oki |
| Okí© |
| Oki Kano |
| Okiah |
| Okid |
| Okieriete Onaodowan |
| Okills |
| Okin |
| Okke Punt |
| Okkervil River |
| Okko |
| Okoumé |
| Oksana |
| Okta Logue |
| Oktay Gürtürk |
| Oktay Özdemir |
| Ol' 55 |
| Ol' dirty bastard |
| Ol Kainry |
| Ol Skool |
| Ola |
| Ola Åkerman |
| Ola Kvernberg |
| Ola Nordmann |
| Ola Salo |
| Ola Svensson |
| Olaf |
| Olaf Berger |
| Olaf Blackwood |
| Olaf Der Flipper |
| Olaf & Hans |
| Olaf Henning |
| Olaf Kübler |
| Olamide |
| OLAN |
| Olav Basoski |
| Olav Mol |
| Olavi Uusivirta |
| Olavi Virta |
| Olazermi |
| Olcay Bolelli |
| Olcayf |
| Old |
| Old 97’s |
| Old 97's |
| Old and New Dreams |
| Old Blind Dogs |
| Old Canes |
| Old Chicago Blues Band |
| Old Crow Medicine Show |
| Old Dead Tree |
| Old Dominion |
| Old Fashioned Revival Hour Choir |
| Old Friends Quartet |
| Old Fulmine |
| OLD HIPPIES ANONYMOUS |
| Old & In the Gray |
| Old & In the Way |
| Old Jaw |
| Old Jawbone |
| Old Man Canyon |
| Old Man Gloom |
| Old Man Luedecke |
| Old Man Of Name |
| Old Man's Child |
| Old Man Saxon |
| Old News |
| Old Notes |
| Old School Freight Train |
| Old School Junkies 2 |
| Old School Players |
| Old Skool Disco Masters |
| Old State |
| OLD STORY PROJECT |
| Old Sweat |
