- O.N
- OBLIVION DUST
- OCEANLANE
- octaviagrace
- ODATOMO
- Ogre You Asshole
- Oh!Sharels
- OJS48
- OKAMOTO´S
- OLD
- OLD LACY BED
- OLDCODEX
- OLEDICKFOGGY
- Omodaka
- On & Off
- One Of A Kind
- ONE OK ROCK
- ONE☆DRAFT
- ON∕OFF
- ORANGE RANGE
- ORIONBEATS
- OTONA MODE
- otori
- Ovall
- OVER ACTION
- Overground Acoustic Underground
- Overhead Champion
- OverTheDogs
- OVUM
- OxT
- OZROSAURUS
- 偶想Drop