- O
- OO
- OO
- OO
- OOaf
- OAFOaK
- OakOBE
- ObeObn
- OBO
- Oce
- OceOCS
- OCTOct
- OctOdd
- OddODE
- ODEOdo
- OdoOf
- OfOff
- OffOff
- OffOgr
- OgrOh
- ohOHM
- OHNOiz
- OizOka
- OkaOkl
- OklOla
- OlaOld
- OldOld
- OldOle
- OleOli
- OliOli
- OLIOls
- OlsOlz
- OmOma
- OmaOme
- OmeOmo
- Omo
- One
- OneOne
- ONEOne
- OneONE
- OneOnl
- OnlONR
- OnsOok
- OokOPE
- OpeOPF
- OPFopt
- OptOra
- OraOrb
- OrbOrc
- OrcOrc
- OrcOre
- OreOrg
- OrgOri
- OriOrk
- OrkOrn
- OrnOrq
- OrqOrr
- OrrOrt
- OrtOsb
- OsbOsc
- OscOsl
- OslOst
- OstOte
- OteOto
- OtoOtt
- OttOub
- OubOur
- OurOut
- OutOut
- OutOut
- OutOve
- OveOve
- OveOwe
- OweOwl
- OwlOxo
- OxoOzc
- OzcOzu
- Ozuozz
- 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
- Octappella (United States contemporary a cappella)
- Octarium
- Octava Dimesión, La (Colombian salsa group in the 1980s/90s)
- Octavarium
- Octave (Iranian Band)
- Octave Band, The
- 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)
- Octaves, Les
- 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
- Octavian Winters
- OCTAVIO
- Octavio Garcia
- 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
- October 31 (US Heavy Metal)
- October Burns Black
- October Changes (Belgian gothic metal band)
- October Country
- October Dogs
- October Drift
- October Ember
- October Ends
- October Ends & Nick Thurl Mavromatis
- October Fall (piano-fueled pop punk band)
- October Falls (Finnish atmospheric black metal)
- October File
- October Game, The (UK alt rock band)
- October Jimmy
- October Light
- October London
- October London & Ledisi
- October London feat. Snoop Dogg
- October Man
- October Noir
- October People
- October Project
- October Rage
- October Rising
- October Sky
- October Tide
- October Tooth (Zachary Threlkeld)
- October, Jonny (NYC rapper)
- Octoberman (Canadian indie rock band)
- Octobre (rock band from Quebec)
- Octobre Rouge (French rap group)
- Ôctôctô
- OctoLab
- Octoploid
- Octoploid feat. Joutsen, Tomi
- Octoploid feat. Koivusaari, Tomi
- Octoploid feat. Kotamäki, Mikko
- Octopus (UK britpop group)
- Octopus (1970s German progressive rock group)
- Octopus (1970s Belgian pop band)
