- 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
- Ornithology (Performance name of Shaan Chhadva)
- Ornob
- ORO (Uruguay)
- Oro Negro (Grupo de Ecuador)
- Oro Sólido
- Oro Swimming Hour
- Oro y Plata, Dueto
- Orobians, The
- Orochen (Post-rock / folk from Sweden)
- OROCHI (2004 Visual Kei Band)
- Orochi (Brazilian rapper)
- Orodruin (Traditional Doom Metal band from U.S.A.)
- Orofino, Richard
- Orok, Shayne
- Orok, Shayne & Orok, Ali
- Öröm
- Oromocto Diamond
- Oronti
- Oropesa, Omar (Christian music singer)
- Ôros Kaù (Belgian black metal)
- Orouni
- Oroza, Bobby
- Oroza, Bobby & El Michels Affair
- Oroza, Bobby feat. Cold Diamond & Mink
- Orozco Barrientos
- Orozco, Alejandra
- Orozco, Antonio (Spanish singer-songwriter)
- Orozco, Antonio & Fonsi, Luis
- Orozco, Antonio & Juanes
- Orozco, Antonio & KAROL G
- Orozco, Antonio & Martín, Dani
- Orozco, Antonio & Pereyra, Luciano
- Orozco, Antonio & Raphael
- Orozco, Antonio & Soledad
- Orozco, Antonio & Yatra, Sebastián
- Orozco, Antonio con Malú
- Orozco, Antonio feat. Fonsi, Luis
- Orozco, Antonio feat. Malú
- Orozco, José Darío
- Orozco, José-Luis
- Orozco, Rafael (pianist)
- Orozco, Regina
- Orozco, Verónica
- Orpair
- Orphan (80's band from Winnipeg, Canada)
- Orphan (deathcore band)
- Orphan Boy
- Orphan Hate
- Orphan Newsboys, The
- Orphan Prodigy
- Orphan Project
- Orphan Songs
- Orphan Swords (Belgian duo)
- Orphan Zero
- Orphanage
- Orphaned Land
- Orphaned Land & Amaseffer
- Orphaned Land feat. Hackett, Steve
- Orphaned Land feat. Koray, Erkin
- Orphaned Land feat. Kürsch, Hansi
- Orphaned Land feat. Lindberg, Tomas
- Orphaned Land feat. Poliker, Yehuda
- Orphaned Land feat. Wilson, Steven
- Orphans, The (West Chester, PA (USA) punk band)
- Orphans, The (Australian power pop)
- orphantwin
- Orpharion
- Orphax (Dutch ambient / drone musician)
- Orphean Passage
- Orphei Drängar
- Orphei Drängar, Sund, Robert
- Orpheus (Australian death metal band)
- Orpheus (1960s–70s Boston rock band)
- Orpheus (masquerade drag artist)
- Orpheus Boys Choir (on 1974 Schonberg BBC cd & 1996 Christmas cd)
- Orpheus Chamber Orchestra (US orchestra)
- Orpheus Nine
- Orpheus Omega
- Orpheus, Aaron
- Orphies
- Orphix
- ORPHY (Kirill Rogovets)
- Orpilla, Ava
- Orplid
- Orquesta (Madrid-based duo)
- Orquesta Akokán
- Orquesta Akokán feat. Oliveros, Carolina
- Orquesta América (Cuban charanga)
- Orquesta América del '55
- Orquesta Aragón
