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