- O
- OO
- OO
- OOak
- OakObi
- ObiOC
- OcaOce
- OceOct
- OctOde
- OdeOdo
- OdoOfe
- OfeOG
- OGOh
- OhOi
- OiOKA
- OkaOku
- OkuOld
- OldOle
- OleOli
- OliOls
- OlsOma
- OmaOmi
- OmiON
- OnaONE
- OneOne
- OneOni
- OniOns
- OnsOos
- OotOph
- OphOr
- OrOrb
- OrbOrc
- OrcOrg
- OrgOri
- OriOrm
- OrmOrq
- OrqOry
- OryOsc
- OscOsm
- OsmOta
- OtaOts
- Ott
- OOut
- OutOut
- OutOv
- OvOve
- OveOwe
- OweOxm
- OxmOzr
- OZZ
- Ona Nua
- ONAIR
- Önal, Ayşe Hatun
- Önal, Füsun
- Onar (Polish MC)
- Onarsé
- Onasis, Ariez
- Onasis, Ariez feat. Cossom, Kevin
- Onasis, Erick
- Oñate, Jorge
- Onay, Gülsin
- ONBC (Danish indie rock)
- Onbeskaamd (Afrikaans worship music project group based in South Africa)
- Once a Pawn
- Once a Tree
- Once Again (Dancefloor project by Michael Schendel, active in the mid 1990s)
- Once and Future Band
- Once Blue
- Once Dead (Heavy Metal from L.A.)
- Once Human
- Once Human feat. Flynn, Robert
- Once Human, Flynn, Robert
- Once Monsters (UK Band)
- Once Never Again (Belgian late 1990s hardcore band)
- Once Nothing
- Once Tiros
- Once Upon a Dead Man
- Once Upon a Time (lead Bruno Adams)
- Once upon a winter
- Once, The
- Öncel, Nazan
- OnCue
- Onda (Michaelangelo L'Acqua & Gregg Fine)
- Onda Sabanera
- Onda Vaga
- Onda Vaselina
- Onda, Carlo
- Onda, Naoyuki
- Ondara, J.S.
- Ondatrópica
- Önder (Turkish hip-hop)
- Onderadio
- Ondina (eurodance vocalist)
- Ondra, Jakub (Czech vocalist, guitarist and songwriter)
- Ondrasik, John
- Ondreaz
- Ondřej Havelka a jeho Melody Makers
- Ondskapt
- Ondt Blod (Norwegian hardcore punk band)
- OnDubGround
- OnDubGround feat. Brother Culture
- One (Greek/Cypriot pop boyband)
- One (Florida hard rock band, affiliated with Sevendust)
- One (UK rap crew, w/ members Sway, Pyrelli, etc.)
- One (UK late 60s psychedelic rock band)
- ONE (South Korean rapper)
- One (80s UK band with Steve Hovington & Seven Webster)
- One 2 (US rapper)
- One 2 Many
- ONE 3rd NOTES
- One Acen
- One Acen feat. WSTRN
- One Adam 12
- One AM Radio, The
- One America (One America)
- One Bad Pig
- One Bad Son
- One Be Lo
- One Be Lo feat. Decompoze
- One Be Lo feat. Kadi
- One Bit & Cyrus, Noah
- One Block Radius
- One Buck Short
- One Chance
- One Chance feat. Fabo
- One Click Straight (Alternative Filipino Band)
- One Cool Guy
- One Day (Australian hip-hop)
- One Day Alive (Heavy Metal Band)
- One Day as a Lion
- One Day Hero
- One Day Remains (Based in Switzerland)
- One Dead Three Wounded
- One Desire (Melodic rock band from Finland)
- One Dimensional Creatures
- One Dimensional Man
- One Direction
- One Dollar Short
- One Dove
- ONE DRAFT