| Op:l Bastards |
| Opal |
| Opal Blue |
| Opal Josephs |
| Opalo y Negros |
| Open Arms |
| Open Form Trio |
| Open Hand |
| Open Mic Karaoke |
| Open Mike Eagle |
| Open Road |
| Opera Steve |
| Opera Trance |
| Operación Triunfo 2017 |
| Operación Triunfo 2018 |
| Operacion Triunfo III |
| Operatic String Orchestra |
| Operation Code 671 |
| Operation Ivy |
| Operator |
| Operator Please |
| Opetaia Foa'i |
| Opeth |
| Opgezwolle |
| Ophelie Winter |
| Ophthalamia |
| Opia |
| Opiate For The Masses |
| Opie |
| Opie Bellas |
| Opio |
| Opium Jukebox |
| Opm |
| Oppenheimer |
| Oppera |
| Opposite Day |
| Oppressor |
| Opshop |
| Opt the Game Hustler |
| Optiganally Yours |
| Optik Crew |
| Optiloop |
| Optimo |
| Optimystic |
| Opus |
| Opus 3 Jazz Trio |
| Opus III |
| Opus Pro |
| Opvs |
| Opwekking |
| Opwekking Crew |
| OQuadro |
| Oques Grasses |
| Oquinto |
| Or |
| OR |
| Or-N-More |
| Ora |
| Oracle |
| Oral Majority |
| Oran "Hot Lips" Page & His Band |
| Oran "Juice" Jones |
| Oran Thaddeus Page |
| Orange |
| Orange 9mm |
| Orange Blue |
| Orange Cake Mix |
| Orange Clubbers |
| Orange Factory |
| Orange Goblin |
| Orange Juice |
| Orange Kellin |
| orange pekoe |
| Orange Range |
| Orange Sherbet |
| Oranger |
| Oranj Symphonette |
| Orba Squara |
| Orbert Davis |
| Orbison, R~Melson |
