- O
- OO
- OO
- OOak
- OakObi
- ObiOBS
- ObtOce
- OceOct
- OctOdd
- OddOdm
- ODMOf
- OfOFK
- OfMOh
- OhOhm
- OhmOjo
- OKOkl
- OklOla
- OlaOld
- OldOli
- OliOli
- OliOly
- OlyOme
- OmeOmo
- OMOOnd
- OndOne
- ONEOne
- OneOnl
- OnlOob
- OobOpe
- OpeOpp
- OppOra
- OraOrc
- OrcOrd
- OrdOrh
- OriOri
- OriOro
- OroOrr
- OrsOs
- OsOsc
- Oscoso
- OsoOte
- OteOtt
- OttOui
- OuiOut
- OutOut
- OutOve
- OveOVE
- Owe
- OweOXO
- Oxo
- OZZ
- Orsa spelmän
- Orselli, Folco
- Orsen
- Orsen, Jack
- Orsen, Jack & Taktloss
- Orsenna, Erik
- Orsi
- orso, L' (Italian band)
- Orsolics, Hans
- Orson (00s US power pop band)
- Orsons, Die
- Orsons, Die feat. Cro
- Orsons, Die feat. Maxim
- Orta, Choco
- Orta, Manuel
- Orta, María (Puerto Rican Christian music singer)
- Ortaç, Serdar
- Ortaçgil, Bülent
- Ortaçgil, Bülent & Kızılok, Fikret
- Ortaçgil, Bülent & Teoman
- Ortak, Svaba (rapper from Austria)
- Ortega, Anthony (jazz saxophonist)
- Ortega, Anthony, Trio
- Ortega, Emanuel
- Ortega, Fernando
- Ortega, Jeannie
- Ortega, Jeannie feat. Papoose
- Ortega, José (designer)
- Ortega, Lindi
- Ortega, Michael
- Ortega, Paco
- Ortega, Palito
- Ortegon, Sr (José Miguel Ortegón)
- Ortelli, Paolo, Matrix, DJ, Party Boomers feat. C, Jay
- Ortero, David
- Orth, Marisa
- Orthentix
- Orthodox (Spanish doom metal)
- Orthodox (Straight Edge)
- Orthodox Celts
- Orthostat
- orti (electronic/electroclash/techno project)
- Orties
- Ortiga (Chilean canto nuevo group)
- Ortiga (Former Esteban & Manuel member)
- Ortiz, Alfredo (player of the Paraguayan harp)
- Ortiz, Bill
- Ortiz, Gerardo (Regional Mexican singer)
- Ortiz, Joell (rapper fka Jo‐ell Quikman)
- Ortiz, Joell feat. Novel
- Ortiz, Kevin
- Ortiz, Luis “Perico”
- Ortiz, Paul y La Orquesta Son
- Ortolani, Riz
- Ortolani, Riz feat. Ranieri, Katyna
- Orton, Beth
- Orton, Beth feat. Callier, Terry
- Orton, Mark
- Ortopedia Técnica (Garage Punk band from Castellón de la Plana)
- ortoPilot
- Ortsul (Poland / Black Metal)
- Oruç, Mustafa
- Orup (Swedish musician Hans Thomas Eriksson)
- Orville Peck
- Orvokki
- Orwell (French band)
- Orwells, The
- Orxata Sound System
- Ory, Kid
- Oryad (doom metal/symphonic metal group)
- Oryema, Geoffrey
- oryl
- Orzabal, Roland
- OS (German duo)
- OS 101
- Os 3 do Nordeste
- Os Atuais
- Os Bardos
- Os Cretinos
- Os Extintos
- Os Garotin
- Os Mateadores
- Os Mulheres Negras
- Os Mundi
- Os Nativos (South-Brazilian gaucho music group)
- Os Pontos Negros
- Os Serranos
- Os The Darma Lóvers
- Os Tincoãs
- Os Vips