- 1 ONSEEON
- 2 ONDD
- 3 Owol
- 4 Onoken
- 5 OHTORA
- 6 ONiLL
- 7 Old Yearning
- 8 oceanfromtheblue(오션)
- 9 Okid
- 10 One Life
- 11 OTIKA
- 12 OTHANKQ
- 13 Orangestar
- 14 ONLEE
- 15 OSUM
- 16 O3ohn
- 17 Omoi
- 18 Odd95
- 19 Off The Topline
- 20 OSSH
- 21 OXYNOVA
- 22 Otis Lim
- 23 ONCE
- 24 OMSB
- 25 OSUN
- 26 Outsider
- 27 Olltii
- 28 oddjun
- 29 Osshun Gum
- 30 Oki