- O
- OO
- OO
- OOak
- OakObi
- ObiObt
- ObuOce
- OceOct
- OctOdd
- OddODM
- ODOOf
- OfOfn
- OfoOH
- OHOHN
- OhnOK
- OKOko
- OkrOld
- OldOld
- OldOli
- OliOll
- OllOm
- OMAOme
- OmeON
- onOne
- OneOne
- OneOne
- OneOnl
- OnlOom
- OomOpe
- OpeOpt
- OptOra
- OraOrc
- orcOre
- OreOri
- OriOrk
- OrkOrp
- OrpOrt
- OrtOsa
- OsbOSH
- OshOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- Oveovl
- OvnOwl
- OwlOys
- OZOZZ
- Orkiestra Dni Naszych
- Orkiestra Uliczna Z Chmielnej
- Orko (UK rock band)
- Orko the Sycotik Alien
- Orkrist
- Orlandi, Violet
- Orlandi, Violet feat. Dan Vasc
- Orlando (Belgian tech house singer)
- Orlando (Italian italo-dance project)
- Orlando Julius (Nigerian saxophonist, singer, bandleader, and songwriter)
- Orlando Marin & His Orchestra
- Orlando Philharmonic Orchestra
- Orlando Pops Orchestra
- Orlando Pops Orchestra & Lane, Andrew
- 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
- 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)
- 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 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)