- 1 OCTOBER
- 2 Orangestar
- 3 Otokaze
- 4 Onoken
- 5 O3ohn
- 6 oceanfromtheblue(오션)
- 7 On.U
- 8 Outsider
- 9 otetsu
- 10 OLDE WORLDE
- 11 Olltii
- 12 OneSun
- 13 Okasian
- 14 Optical Eyez XL
- 15 Oki
- 16 Odee
- 17 osterreich
- 18 O!Gon
- 19 ONE
- 20 Owen Ovadoz
- 21 One Up (원업)
- 22 One Life
- 23 One
- 24 OFA
- 25 Owol
- 26 Ohwon Lee (진짜사나이)
- 27 OVER ARM THROW
- 28 OLFA ASTRA
- 29 OVAN
- 30 O.S.T