- 1 OneRepublic
- 2 One Direction
- 3 Owl City
- 4 Oasis
- 5 O-Zone
- 6 Oh Wonder
- 7 Oh The Larceny
- 8 Odesza
- 9 Of Monsters And Men
- 10 Opeth
- 11 Outkast
- 12 Outlandish
- 13 Ofenbach
- 14 Oomph!
- 15 Oneira
- 16 One-T And Cool-T
- 17 Otto Le Blanc
- 18 ONUKA
- 19 Orchestral Manoeuvres in the Dark
- 20 Our Last Night
- 21 Origen
- 22 Old Dominion
- 23 Overground
- 24 Oceanlab
- 25 O-Town
- 26 One Voice
- 27 Oberhofer
- 28 of Montreal
- 29 Old Man Canyon
- 30 OU