- 1 OneRepublic
- 2 One Direction
- 3 Owl City
- 4 Oasis
- 5 O-Zone
- 6 Oh Wonder
- 7 OK Go
- 8 Oh The Larceny
- 9 One-T And Cool-T
- 10 Odesza
- 11 Overground
- 12 Our Last Night
- 13 ONUKA
- 14 Origen
- 15 Old Dominion
- 16 Old 97's
- 17 Old Man Canyon
- 18 Ofenbach
- 19 Otherwise
- 20 Outkast
- 21 Outlandish
- 22 Oceanlab
- 23 Otros Aires
- 24 Of Monsters And Men
- 25 Orchestral Manoeuvres in the Dark
- 26 O-Town
- 27 of Montreal
- 28 Our Lady Peace
- 29 Ocean Colour Scene
- 30 Oh No! Oh My!