- O
- OO
- OO
- OOak
- OakObi
- ObiObt
- ObtOce
- OceOct
- OctOdd
- OddODM
- ODOOf
- OfOfn
- OfnOh
- OhOhm
- OhmOK
- OKOkm
- OKOOla
- OlaOld
- OldOli
- OliOll
- OllOly
- OlyOME
- OmeOMP
- OmpOnD
- OneONE
- ONEOne
- OneOnl
- OnlOOJ
- OojOpe
- OpeOpp
- OppOra
- OraOrc
- OrcOre
- OreOri
- OriOri
- OriOrp
- OrpOrs
- OrtOsa
- OsaOse
- OshOss
- OssOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOvi
- OviOwl
- OwlOxy
- OyOzu
- OzuOZZ
- Oceans of Slumber
- Oceans of Time
- Oceans on Orion
- Oceans Red
- Oceans, The
- Oceanship
- Oceanside85
- Oceansize
- Oceanspeak
- Oceanus (future disco)
- Oceanwake
- Oceill
- Ocelots, The (Irish indie folk duo)
- Oceransky, Edgar
- Ochaion, Kfir
- Ocher, Mary
- Ochman (Polish singer-songwriter Krystian Ochman)
- Ochman & @Atutowy
- Ochmoneks (from Düsseldorf Germany)
- Ocho
- Ocho Macho
- Ocho y Media
- Ochoa, Amparo
- Ochoa, Eliades
- Ochoa, Eliades y el Cuarteto Patria
- Ochoa, Kelvis
- Ochoa, Rolando
- Ochobre
- Ochre (electronic musician Christopher Leary, UK)
- ochre (Scottish post-punk band)
- Ochs, Conny
- Ochs, Phil
- Ocie Elliott
- Ócio (Brazilian rock band)
- Ock, Sam
- Ockeghem, Johannes (Franco-Flemish early Renaissance composer)
- Ockert, Darren
- Ockham’s Razor (folk rock quartet based out of Seattle)
- OCN
- OCnotes
- Oco Yajé feat. Calderón, Daniel, Mackie, J Álvarez, Yelsid & Kapry, Marlon
- Ocote Soul Sounds
- OCS
- OCS (dutch rapper)
- OCT
- Octafonic
- Octagon, Dr.
- Octagon, Dr. feat. Dexter
- Octahvia (US house/dance vocalist Octavia Lambertis)
- Octale (Belgian progressive metal band)
- Octane (Philadelphia hard rock band)
- Octane & DLR
- Octane & DLR feat. Marion
- Octarium
- Octava Dimesión, La (Colombian salsa group in the 1980s/90s)
- Octavarium
- Octave Cat
- Octave Lissner
- Octave Minds (Chilly Gonzales and Boys Noize collaboration)
- Octave Minds feat. Chance the Rapper & Social Experiment, The
- Octave Noire (formerly known as Oh Morice)
- Octave One (Burden brothers, US techno producers)
- Octave One feat. Saunderson, Ann
- Octaves (US hardcore band from Baltimore, MD)
- Octavia (Bolivian pop)
- Octavia Sperati (Norse gothic metal band)
- Octavia Wakes
- Octavian (South-London based rapper)
- Octavian feat. ABRA
- Octavian feat. ASAP Ferg
- Octavian feat. J Rick & Ware, Jessie
- Octavian feat. London, Theophilus
- Octavian feat. Skepta & Phantom, Michael
- Octavian feat. Smokepurpp
- Octavian Ft. Future
- Octavian ft. Gunna & SAINt JHN
- Octavian ft. Phantom, Michael
- Octavian ft. Skepta
- OCTAVIO
- Octavio Mai (French electronic/alternative duo of Juliette Bazenet and Johan Putet)
- Octavio the Dweeb
- Octavus Lupus (Symphonic metal band from Lieusaint, Île-de-France)
- octi
- Octinomos
- OCTiV
- OCTiV feat. Celldweller
- Octo Octa
- October 31 (US Heavy Metal)
- October Burns Black
- October Country