- 1 OCTOBER
- 2 Outsider
- 3 Orangestar
- 4 OTHANKQ
- 5 Otokaze
- 6 ONE
- 7 Onoken
- 8 Omoi
- 9 OVAN
- 10 oceanfromtheblue(오션)
- 11 O'Domar
- 12 Osshun Gum
- 13 Olltii
- 14 Okasian
- 15 otetsu
- 16 Ourealgoat
- 17 OSUN
- 18 On.U
- 19 OLDE WORLDE
- 20 OneSun
- 21 Optical Eyez XL
- 22 Oki
- 23 Odee
- 24 OJ
- 25 osterreich
- 26 O!Gon
- 27 Ottiki
- 28 Owen Ovadoz
- 29 One Up (원업)
- 30 One Life