- Oporto
- Opossum
- Opossum Gang
- Opossum Holler
- OposSUM und die Beutelratten
- Opotopo
- Opozycja
- Oppas
- Oppenheimer
- Oppera
- Oppnedbass
- Opponents
- Oppong's Guitar Band
- Opportunity School
- Opposable Thumbs
- Oppose
- Opposed to Violence
- Opposing Forces
- Opposite
- Opposite Corner
- Opposite Day
- Opposite Earth
- Opposite Exhale
- Opposite Pole
- Opposite Poles
- Opposite Sex
- Opposite Six
- Opposite The Satellite
- Opposite Worlds
- Opposition
- Opposition of O
- Opposition of One
- Opposition Party
- Opposition Rising
- Oppressed By The Line
- Oppressed Logic
- Oppressor
- Opprobrium
- OPQ
- Oprachina
- Oprah Winfrey
- Opram
- Oprica Ivancea
- Oprlid
- OPS
- Opshop
- Opstand Choir
- Opsvik & Jennings
- Opt the Game Hustler
- OPT4red
- Optamus
- Opthalamia
- Opti
- Opti-Grab
- Optic
- Optic Axis
- Optic Eye