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