- O
- OO
- OO
- OO
- OOaf
- OAFOaK
- OakOBE
- ObeObn
- OBO
- Oce
- OceOCS
- OCTOct
- OctOdd
- OddODE
- ODEOdo
- OdoOf
- OfOff
- OFFOfi
- OfiOgr
- OgrOh
- OhOHN
- OhnOiz
- OJOKA
- OkaOkm
- OKOOla
- OlaOld
- OldOld
- OldOle
- OleOli
- OliOli
- OLIOls
- OlsOma
- OmaOma
- Omaomg
- omgOmo
- OmoO
- OnaOne
- OneOne
- OneOne
- ONE
- OneOnl
- OnlONT
- ontOom
- OomOpe
- OpeOph
- OphOpt
- OpuOra
- OraOrb
- OrbOrc
- OrcOrc
- OrcOre
- OreOri
- OriOri
- OriOrk
- OrkOro
- OroOrq
- OrqOrs
- OrsOru
- OruOsb
- OsbOsc
- OscOSM
- OsmOst
- OstOte
- oteOtr
- OtrOtt
- OttOui
- OuiOus
- OusOut
- OutOut
- OutOut
- OutOve
- OveOVE
- OveOwe
- oweOwn
- OwnOxy
- Oxy
- OZZ
- ozzozz
- Opuntia (solo project of Mexico City producer Camila de Laborde)
- Opus (Austrian band; track: “Live Is Life”)
- Opus & Ambros, Wolfgang
- Opus & S.T.S.
- Opus 4 (French gipsy swing quartet)
- Opus 78
- Opus Alfa
- Opus Atlantica
- Opus Avantra
- Opus Cuatro
- Opus Däi
- Opus featuring Buchebner, Erich, Schiffkowitz and Timischl, Günter
- Opus featuring Falco
- Opus featuring Gruber, Peter Niklas
- Opus featuring Kolonovits, Christian
- Opus featuring Musenbichler, Robby
- Opus III (English techno and house music)
- Opus III (Swedish trio)
- Opus Kink
- Opus Orange
- Opus Pro
- Opus X (Finnish classical ensemble)
- Opus X (Scandinavian pop)
- Opus.
- Opvs Nostri
- oqbqbo
- OQuadro
- Oquendo, Manny y Libre
- Oquendo, Manny's Libre
- Oques Grasses
- Oques Grasses & Doble
- Oques Grasses & Payés, Rita
- Oques Grasses & Santa Salut
- Oques Grasses & Stay Homas
- Oques Grasses, Al·lèrgiques al pol·len
- Oques Grasses, Figa Flawas
- Oques Grasses, Julieta
- OQueStrada
- OR (rap duo)
- Or Bleu
- Or Bleu featuring Lary Kidd
- Or du Commun, L’ (Belgian hiphop)
- Or du Commun, L’ feat. Elvis, Roméo
- Or du Commun, L’ feat. Elvis, Roméo, Caballero, Zwangere Guy
- Or du Commun, L’ feat. Lous and the Yakuza
- Or Noir (French TV show)
- Or-N-More
- Or, Rotem
- Or, Rotem
- Or, The Whale
- OR3O (fandom music producer/vocalist)
- OR3O & The Musical Ghost
- OR3O feat. Plexsy & Silva Hound
- Ora (Andrew Chalk & Darren Tate)
- Ora (late 1960s UK psychedelia)
- ORA (classical choir)
- ORA (Danish duo)
- Ora Mate
- Ora the Molecule
- Ora, Rita
- Ora, Rita & Limani, Yll
- Ora, Rita feat. Brown, Chris
- Ora, Rita feat. Cardi B, Rexha, Bebe & Charli xcx
- Ora, Rita feat. Cole, J.
- Ora, Rita feat. Fatboy Slim
- Ora, Rita feat. Michaels, Julia
- Ora, Rita feat. Tempah, Tinie
- Ora, Rita feat. will.i.am
- Ora, Rita x Guetta, David x Imanbek
- Ora, Rita x Guetta, David x Imanbek feat. Gunna
- Ora, Rita x Imanbek feat. Khea
- Orachi, Alec
- Oracle (Indonesian Thrash Metal band)
- Oracle (Heavy Metal band from Gibraltar)
- ORACLE & Fractures
- ORACLE & Holochrome
- Oracle Hands (German Sludge/Post-Metal band)
- Oracle Sisters (Band from Paris, France)
- Oracle Spectre (Deathcore from California)
- Oracles (indie psychedelic rock band from Berlin)
- Oraculum (US Progressive Metal/Shred band)
- Orage, L (from Italy)
- Orage, L’ (Swiss jazz ensemble from Geneva)
- Orai (Lithuanian post-punk band)
- Orakle
- Oral Bee (Norwegian rapper)
- Oral Bee & Da Playboy Foundation
- Oral Bee & Kholebeatz
- ORAL CIGARETTES, THE
- Oral Tunerz starring Whigfield
