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