- O
- OO
- OO
- OO
- OOAF
- OAFOak
- OakObe
- ObeObo
- OboOca
- OCBOce
- OceOct
- OctOCT
- OctOdd
- OddODE
- ODEOdu
- OduOf
- OfOff
- OffOfn
- OfnO
- OOh
- OhOHo
- OHROje
- OjeOKA
- OKAOku
- OkuOla
- OlaOld
- OldOle
- OlOli
- OliOli
- OliOll
- OllOls
- OlsOma
- OmaOme
- OmeOmn
- OmnOn
- OnOnd
- OndOne
- OneOne
- OneOne
- OneOni
- OniOnm
- OnMOny
- OnyOot
- OotOpe
- OpeOpp
- OppOr
- OrOra
- OraOrb
- OrbOrc
- OrcOrd
- OrdOrg
- OrgOri
- OriOri
- OriOrl
- Orlorp
- OrpOrq
- OrqOrt
- OrtOsa
- OsaOsc
- OscOsk
- oskOss
- Oss
- Oti
- OtiOtt
- Ott
- Our
- OurOut
- OutOut
- OutOut
- OutOve
- OveOve
- OveOwe
- OweOwl
- OwlOXO
- Oxo
- Ozu
- Ozuozz
- Oppidan & Frisco
- Oppidan & Pocket
- Oppidan & venbee
- Öppna Korten
- Opposing Force (Bay Area Hardcore Band)
- Opposite the Other
- Opposites, The
- Opposites, The feat. Adje
- Opposites, The feat. Faberyayo & Sjaak
- Opposites, The feat. Hydroboyz & Adje
- Opposites, The feat. Probz, Mr
- Opposites, The feat. Probz, Mr.
- Opposites, The feat. Sef
- Opposites, The feat. Spasmatic
- Opposites, The met Yellow Claw
- Opposition of One
- Opposition, The (London post‐punk band)
- Oppressed, The (Welsh punk/oi)
- Oppressor (US technical death metal)
- Opprobre
- Opprobrium
- Opraah
- OPROER (Belgian indie rock band)
- Oproprio, Yago
- Oproprio, Yago & Patricio Sid
- Opsa Dehëli
- Opshop
- Opskamatrists, The
- Opsomer, Barbara (Belgian singer)
- Opstad, Jon
- Opti-Pop
- Optic
- optic core (experimental electronic/dance producer)
- Optic Nerve, The (80s NY garage rock band)
- Optic Sink
- Optical (UK drum & bass producer Matt Quinn)
- Optical 2
- Optiganally Yours
- Óptimo (bachata group/artist)
- Optimus (US rapper, aka Jordy Towers)
- Optimus Rhyme (US nerdcore hip hop group)
- Optiv & BTK
- Optiv & BTK feat. Ryme Tyme
- Optometry (John Tejada & March Adstrum)
- 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)
