- O
- OO
- OO
- OO
- OO
- OOak
- OakObe
- ObeOBL
- OblObs
- Obsoce
- OceOce
- oceOct
- OctOda
- OdbOdd
- OddOde
- OdeODU
- ODUOf
- OfOff
- OFFOfi
- Ofiogo
- OGROh
- OhOhi
- OhiOIL
- OilOk
- OkOke
- OkeOl
- OlOla
- OlaOld
- OldOl
- OlOlg
- OlgOli
- OliOli
- OliOls
- OlsOMA
- OmaOma
- OmaOme
- OmeOmn
- OmnOn
- OnOne
- ONEOne
- OneOne
- OneOne
- OneONJ
- OnkOnn
- ONOOny
- OnyOos
- OosOpe
- OpOpi
- OpiOpu
- OpuOra
- Oraorb
- OrbOrc
- OrcOrc
- OrcOre
- OreOrh
- OrhOri
- ORIOrk
- OrkOrn
- OrnOrq
- OrqOrr
- OrrOrt
- OrtOsa
- OsaOsc
- OscOsk
- OskOss
- OssOT
- OtaOth
- OthOtt
- OttOtt
- OttOur
- OurOut
- OutOut
- OutOut
- OutOv
- OvOve
- OveOve
- OveOwe
- OweOwl
- OwlOxl
- Oxl
- OzaOzo
- OzoOzz
- On Tonight
- On Video
- On Water (US metal band)
- On Wave (indie)
- On Your Feet, Original Broadway Cast of
- On-lyne (Warframe fictional boy band)
- ON-OFF (AC/DC cover band from northern Italy)
- On-The-Go
- On, DJ
- ON! (aka Tequila & the Sunrise Gang) (German punk-rock band)
- On!Air!Library!
- ON/OFF (Japanese Band)
- On/Off (Dutch techno duo)
- ON3
- Ona
- Ona Mae
- Ona Nua
- Onabule, Ola
- Onabule, Ola & Brothers, Hazelrigg
- ONAIR
- Önal, Ayşe Hatun
- Önal, Füsun
- Onar (Polish MC)
- Onar gościnnie Lerek
- Onarsé
- Onasis, Ariez
- Onasis, Ariez feat. Cossom, Kevin
- Onasis, Erick
- Oñate, Jorge
- Oñate, Jorge & López, Álvaro
- Oñate, Jorge y Peña, Christian Camilo
- ONBC (Danish indie rock)
- Onbeskaamd (Afrikaans worship music group based in South Africa)
- Once (Germany)
- Once a Pawn
- Once a Tree
- Once and Future Band
- Once Below Joy (Charlotte, NC progressive rock)
- Once Blue
- Once Dead (Heavy Metal from L.A.)
- Once Grace Forever
- Once Human
- Once Monsters (UK Band)
- Once Monsters, Adams, Chloe
- Once Nothing
- Once Tasted Life
- Once Tiros
- Once Upon
- Once Upon a Dead Man
- Once Upon a Time (lead Bruno Adams)
- Once upon a winter
- Once, The
- Öncel, Nazan
- Öncel, Nazan & Manuş Baba
- OnCue
- Ond Cirkel
- Onda (Michaelangelo L'Acqua & Gregg Fine)
- ONDA ANDAR
- Onda Sabanera
- Onda Vaga
- Onda Vaga & Perotá Chingó
- Onda Vaga & Serrano, Jorge
- Onda Vaselina
- Onda, Carlo
- Onda, Naoyuki
- Ondagranda (Italian duo Dargen D’Amico & Emiliano Pepe)
- Ondanaconda
- Ondara, J.S.
- Ondas Marteles, Las
- Ondastral
- Ondatrópica
- Önder (Dutch-Turkish rapper Önder Doğan)
- Önder, Seda
- Onderadio
- Onderkoffer
- Onderwater, Jeska
- Ondes Martenot, Les
- Ondina (eurodance vocalist)
- Ondolindë (Turkish Melodic Death Metal)
- Ondra, Jakub (Czech vocalist, guitarist and songwriter)
- Ondreaz
- Ondrej Ďurica
- Ondřej Havelka a jeho Melody Makers
- Ondskapt (Swedish black metal)
- Ondt Blod (Norwegian hardcore punk band)
- OnDubGround
- OnDubGround feat. Brother Culture
- One (Greek/Cypriot pop boyband)
- One (Florida hard rock band)
- One (UK rap crew, w/ members Sway, Pyrelli, etc.)
