- 1 Opius
- 2 ONDD
- 3 Ourealgoat
- 4 oceanfromtheblue(오션)
- 5 O!Gon
- 6 OHTORA
- 7 OTWO
- 8 Osshun Gum
- 9 One Life
- 10 ONCE
- 11 OSSH
- 12 OVAN
- 13 Otokaze
- 14 ONiLL
- 15 ONSEEON
- 16 oddjun
- 17 oWHo
- 18 ODD Cloud
- 19 OTIKA
- 20 Olltii
- 21 Old Yearning
- 22 Outsider
- 23 Orangestar
- 24 OonG
- 25 Okid
- 26 offen
- 27 Otis Lim
- 28 ORCHID
- 29 ONDA
- 30 Option