- O
- OO
- OO
- OO
- OO
- OOak
- OakObe
- Obeobl
- OblObs
- ObsOce
- OceOch
- OchOct
- OctODC
- OddOdd
- OddOde
- OdeODU
- ODUof
- OfOff
- OFFOfM
- OfMOgr
- OGROh
- OhOhi
- OhjOim
- OinOK
- OKOke
- OkeOl
- OlOla
- OlaOld
- OldOle
- OleOlh
- OLIOli
- OliOli
- OliOls
- OlsOma
- OmaOma
- OmaOme
- OmeOmn
- OmnOn
- OnONE
- OneOne
- OneOne
- OneOne
- oneOnk
- OnkOno
- OnoOny
- OnzOos
- OotOpe
- OpeOpo
- OpoOQu
- OquOra
- OraOrb
- OrbOrc
- OrcOrd
- OrdOre
- OreOri
- OriOri
- OriOrk
- OrkORO
- OroOrq
- OrqOrs
- OrsOrt
- OrtOsb
- OsbOsc
- OscOsl
- OslOst
- OtaOti
- OtiOtt
- Ottott
- OTTOur
- OurOut
- OutOut
- OutOut
- OUTOV
- OVOve
- OveOVE
- OVEOwe
- OweOwl
- OwlOxm
- OxmOza
- OzaOzo
- OzoOzz
- Ó (Formerly Eskimeaux)
- O (Martin Damm, techno)
- O (Olivier Marguerit)
- O (Black metal/Grindcore from Italy)
- Ö (Nicolas Petitfrère, aka Nömak)
- O & The Mo
- o Bardo e o Banjo (Brazilian bluegrass band)
- Õ C'EST NOUS
- o Cantador, Santanna
- O Captain! My Captain! (German acoustic punk band)
- Ó Ceannabháin, Eoghan (Irish folk musician)
- O Conqueror (Austin, TX folk-rock)
- Ó do Forró
- O Emperor (five-piece rock band from Waterford, Ireland)
- O Inimigo
- O Kannalha
- Ö la Palöma Boys
- Ô Lake
- O Lethe
- O Linea
- Ó Lionáird, Iarla
- Ó Maonlaí, Liam
- O Melhor de MPB
- O Mer
- Ô Paon
- O Pioneers!!!
- O Positive
- O Quarentener Só
- O Safari (synth pop duo from Rennes)
- O Samuli A
- O Satânico Dr. Mao e os Espiões Secretos (Brazilian Punk Band)
- Ó Sé, Seán
- O SIDE MAFIA (O $IDE MAFIA)
- Ó Snodaigh, Rónán
- Ó Súilleabháin, Diarmuid
- Ó Súilleabháin, Mícheál (pianist and composer)
- O Terno
- O Verme Vencedor
- o Visitante, Luiz
- O-Hum (Iranian band)
- O-Shen
- O-Zone Percussion Group, The
- O‐Town
- O‐Zone (Moldovan eurodance pop group)
- O, Ashley (fictional pop star from Black Mirror TV series)
- O, Bobby
- O, Coco (Danish singer)
- O, Karen
- O, Karen & Danger Mouse
- O, Karen and Kids, The
- O, Karen with Reznor, Trent and Ross, Atticus
- O, Rodney
- O, Rodney & Cooley, Joe
- O, The (Alt. rock band from New York)
- O!Kult
- O. (Tash Keary & Joe Henwood)
- O. Cas
- O. Children
- O., Jenny
- O., Jens
- O., Jens vs. Special D.
- O., Olivia (US indie singer-songwriter; member of Lowertown)
- O., OSKAR
- O.A.KLAY
- O.A.R.
- O.A.R. feat. Marvin, Junior
- O.A.S.I.
- O.B.F.
- O.B.F. & Charlie P
- O.B.F. & Pupajim
- O.B.F. & Sr. Wilson
- O.B.F. feat. Belén Natalí
- O.B.F. feat. Charlie P
- O.B.F. feat. Charlie P & Belén Natalí
- O.B.F. feat. Junior Roy
- O.B.F. feat. Nazamba
- O.B.F. feat. Sr. Wilson
- O.B.F. feat. Williamz, Mr.
- O.B.M Notion
- O.C. (East-Coast US rapper Omar Credle)
- O.C. & AG
- O.C. feat. Big L
- O.C. feat. Chubb Rock & Jeru the Damaja
- O.C. feat. Ja Shawn
- O.C. feat. Organized Konfusion
- O.C. Supertones, The
- O.C.A & Fede Meyer
- O.C.A.D (Olivia Cipolla and Arie Dixon)
- O.Children
- O.F.T.B. feat. Jewell
