- 1 OneRepublic
- 2 One Direction
- 3 Oasis
- 4 Owl City
- 5 Outkast
- 6 O-Zone
- 7 Oh Wonder
- 8 Oh The Larceny
- 9 OK Go
- 10 One-T And Cool-T
- 11 Odesza
- 12 Of Monsters And Men
- 13 Odd Mob
- 14 Overground
- 15 Onyx
- 16 OBB
- 17 Our Lady Peace
- 18 Oceanlab
- 19 Ocean Colour Scene
- 20 Oh No! Oh My!
- 21 Obituary
- 22 O.A.R.
- 23 Oceana
- 24 Outloud
- 25 OtherView
- 26 Orbital
- 27 of Montreal
- 28 Ozomatli
- 29 OZMA
- 30 Our Last Night