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