- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOCE
- OceOct
- octOdd
- OddOdi
- OdiOf
- OfOff
- OffOh
- ohohG
- OhgOji
- OJMokh
- OKIOla
- OlOld
- OldOli
- OliOli
- OliOls
- OlsOMB
- OMBOmn
- OmnOnb
- OncOne
- OneOne
- OneOni
- ONJont
- OntOos
- OotOph
- OphOR
- OrOrb
- OrbOrc
- OrcORE
- OreOri
- OriOrl
- OrlOrp
- OrpOrt
- OrtOsb
- OsbOsi
- OsiOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOvi
- OviOwl
- OwlOye
- Ozy
- OzzOZZ
- Orlando Riva Sound
- Orlando Vera Cruz
- Orlando, Bobby (US record producer, indie record label owner, songwriter & musician)
- Orlando, Courtney (singer-songwriter, FKA J.R.)
- Orlando, Johnny (Canadian singer-songwriter, vlogger and actor)
- Orlando, Johnny (reggae artist)
- Orlando, Johnny & BENEE
- Orlando, Johnny & kenzie
- Orlando, Ramón
- Orlando, Tom (artist from Ottawa, Ontario, Canada)
- Orlando, Tony
- Orlando, Tony & Dawn (1970s pop group)
- Orlane
- Orleans
- Orleya
- Orlik (czech Oi!)
- Orloff, Peter
- Orloge Simard
- Orlons, The
- Orlova, Alina
- Orlowski, Kris
- Orlowsky, David
- Orlowsky, David, Trio
- ORM (Epic/Melodic Black Metal band from Denmark)
- Ormai
- Ormandy, Eugene (conductor)
- Ormandy, Eugene & Philadelphia Orchestra, The
- Ormåsen, Gaute
- Orme, Le
- Ormiston
- Ormonde
- Orna
- Ornament (Afghan Whigs and Marcy Mays)
- Ornaments (Italian band)
- Ornatos Violeta
- Orne
- Ornelas, Raúl
- Ornella Napolitani
- Ornette (French–Italian singer‐songwriter multi‐instrumentalist)
- Ornithology
- ORO (Uruguay)
- Oro Sólido
- Oro Swimming Hour
- Orochen (Post-rock / folk from Sweden)
- Orochi (Brazilian rapper)
- Orofino, Richard
- Öröm
- Oropesa, Omar (Christian music singer)
- Oros (Slovakian goregrind)
- Ôros Kaù (Belgian black metal)
- Oroza, Bobby
- Oroza, Bobby feat. Cold Diamond & Mink
- Orozco Barrientos
- Orozco, Alejandra
- Orozco, Antonio (Spanish singer-songwriter)
- Orozco, Antonio & KAROL G
- Orozco, Antonio feat. Fonsi, Luis
- Orozco, Antonio feat. Malú
- Orozco, José-Luis
- Orozco, Regina
- Orozco, Verónica
- Orphan (deathcore band)
- Orphan Boy
- Orphan Hate
- Orphan Newsboys, The
- 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
- orphantwin
- Orphax (Dutch ambient / drone musician)
- Orphean Passage
- Orphei Drängar
- Orphei Drängar, Sund, Robert
- Orpheus (Australian death metal band)
- Orpheus (60s/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 Ensemble, The
- Orpheus Nine
- Orpheus Omega