- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOce
- OceOct
- OctOdd
- OddOde
- OdeOeh
- OelOff
- OffOge
- OgeOh
- OhOi
- OiOKA
- OkaOku
- OkuOld
- OldOld
- OldOli
- OliOli
- OliOls
- OlsOmb
- OmbOmn
- OmnOnc
- OncOne
- OneOne
- OneOni
- ONIOno
- OnoOom
- OomOpe
- Ope
- OptORA
- OraOrc
- OrcOrd
- OrdOri
- OriOri
- OriOrn
- OrnOrq
- OrqOru
- OruOsb
- OsbOsi
- OsiOst
- OTH
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOVE
- OVEOwe
- OweOxm
- OxmOzo
- OzoOZZ
- Oceana (German soul singer)
- Oceana & Frank, Kim
- Oceanator (Elise Okusami)
- Oceanborn
- oceanfromtheblue (Korean singer)
- Oceanhoarse
- Oceania (New Zealand, Hinewehi Mohi & Jaz Coleman)
- Oceanic (90s UK pop group)
- Oceanic (DJ & producer Job Oberman)
- OceanLab
- OceanLab feat. Emery, Gareth
- OceanLab feat. Suissa, Justine
- OCEANLANE
- Oceanless (Manchester based, Birmingham band)
- Oceano (American deathcore band)
- Océano de Sangre
- Oceans (Kiz aka Kiz Keyz)
- Oceans (post‐metal/metalcore)
- Oceans Above (Christian Worship Band)
- Oceans Ate Alaska
- Oceans Ate Alaska feat. Teyen, Alex
- Oceans Divide
- Oceans of Slumber
- Oceans of Time
- Oceans on Orion
- Oceans Red
- Oceans, The
- Oceans/Earth Caller
- Oceanship
- Oceanside85
- Oceansize
- Oceanspeak
- Oceanus (future disco)
- Oceanus Orientalis
- Oceanus Orientalis & Mese, Idil
- 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
- Ochunism
- Ocie Elliott
- Ócio (Brazilian rock band)
- Ock, Sam
- Ockeghem, Johannes (Franco-Flemish early Renaissance composer)
- Ockeroid
- Ockert, Darren
- Ockham’s Razor (folk rock quartet based out of Seattle)
- OCN
- OCnotes
- 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)