- O
- OO
- OO
- OOak
- OakObe
- ObeObs
- ObsOce
- Oceoch
- OchOct
- OctOde
- OdeOdo
- OdoOfa
- OfaOff
- OffO
- OOha
- OhaOiz
- OizOKA
- OKAOl
- OlOld
- OldOle
- OleOli
- OliOli
- OliOls
- OlsOma
- OmaOml
- OmmOn
- OnOne
- OneOne
- OneOne
- OneOnl
- OnlOny
- OnyOpe
- OpeOpi
- OpiOra
- OraOrb
- OrbOrc
- OrcOre
- OreOri
- OriOrk
- OrkOro
- OrpOrr
- OrrOrw
- OrwOsb
- OsbOsk
- OskOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOva
- OvaOve
- OveOwe
- OweOxb
- Oxe
- OzeOZZ
- Ones, The (US EDM band)
- Ones, The (80s Punk n' Roll band from Milwaukee, WI)
- Onesa, Paolo
- OneSideZero
- Onestar (former member of Monday Kiz)
- Onete, Dona
- Onething Live (Live Recordings from Onething Conference)
- Onetox (Solomon Island reggae/ragga band)
- onett
- Onetwo (synthpop duo Claudia Brücken & Paul Humphreys)
- OneUp Studios
- OneUps, The
- ONEUS
- OneVoice
- OneVoice Gospel Choir
- ONEW (Lee Jin-ki, member of SHINee)
- ONEWE
- ONEWE & ONEUS
- Oneworld (Dave Randall & friends)
- OneWorld (Current Solo project Sander van der Waal)
- Onexx (Crossover Band from Bonn, Germany)
- Oney (hard rock)
- Öney, Feryal
- Oney1
- ONF
- Ong, Daryl
- Ong, Olivia
- Ongala, Remmy & Orchestre Super Matimila
- Ongoing Concept, The
- Onheil (Dutch blackened/melodic thrash/death metal)
- ONI (Canadian Progressive Metal Band)
- Oni Cea$
- ONI INC.
- Oni Rock (Brazilian rock band)
- ONI, Jones, Howard & Gilbert, Josh
- ONIGAWARA
- Onike, Abdul
- Onile, Marie
- Onion Flavored Rings
- ONIONRING (Japanese rock band)
- Onionz
- Onionz feat. S.n.o.w
- Onirama
- Oniric (Italian dark folk duo)
- Onirismo
- Onirophagus
- Onis, Manuel
- Onishi, Junko, Trio
- Onision
- Onitsha
- Onitsuka, Chihiro
- Ónix Ensamble (Mexican chamber music group)
- Oniyama, Josephine
- ONJ, JON
- ONJUICY (Japanese grime MC and electronic musician)
- Onk Lou
- Onkalo (Finnish doom metal band)
- Onkar, Dan
- Onkel Kånkel & His Kånkelbär (The Band)
- Onkel Tom Angelripper
- Onkel Tuka
- OnklP
- OnklP & Slektningene, De Fjerne
- ONLAP (Alternative Rock band from Paris)
- Online (canadian hip hop)
- onlinefriends
- Onlooker (UK garage punk)
- Only (Album “Immortal”)
- ONLY (Berlin screamo band)
- Only Attitude Counts (Vienna Style Hardcore Kings)
- Only Boys Aloud
- Only Child (UK DJ/Producer Justin Crawford)
- Only Child (US Hard Rock Band)
- Only Child Tyrant
- Only Crime
- Only Emily
- Only Fire
- Only Ghost In Town
- Only Girl
- Only Liars
- Only Living Witness
- Only Men Aloud (Welsh men’s choir)
- Only Monsters
- Only Murders in the Building – Cast
- Only One Felipe
- Only One Ronin (Oakland based rapper)
- Only Ones, The
- Only Real
- Only Rivals (Rock band from Dublin, Ireland)
- Only Rivals (Only Rivals)
