- 1 OneRepublic
- 2 One Direction
- 3 Oasis
- 4 Owl City
- 5 O-Zone
- 6 One Voice
- 7 Oh Wonder
- 8 OU
- 9 Oh The Larceny
- 10 Odesza
- 11 One-T And Cool-T
- 12 Ofenbach
- 13 Of Monsters And Men
- 14 Our Last Night
- 15 Outkast
- 16 Overground
- 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 Orbital
- 26 of Montreal
- 27 Ozomatli
- 28 OZMA
- 29 O-Town
- 30 Outlawz