- 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
- Outrage (French punk-rock band)
- Outrage (Japanese thrash metal)
- Outrageous Cherry
- Outre (Polish black metal band)
- Outright (Australian hardcore band)
- Outro Giovane
- OUTROEU
- Outrun the Fall
- Outrun the Gun
- Outrun the Sunlight
- Outs, The (Brazilian band)
- Outsaiders, Los
- Outshine (Swedish Gothic Metal Band)
- Outshyne (Country Band)
- Outsidaz
- Outside (UK acid jazz group)
- Outside
- Outside Agency, The
- Outside Broadcast Recordings (Meditation)
- Outside Edge
- Outside the Circle (Costa Rica's progressive metalcore band)
- Outsider (Korean male rapper)
- Outsider, The (Solo Post Rock project from Palermo)
- Outsiders (Psytrance artists Haim Lev & Guy Malka from Israel)
- Outsiders feat. Wilson, Amanda
- Outsiders, The (60's Dutch psychedelic band)
- Outsiders, The (60's USA pop/rock band)
- Outsiders, The (electro/house artist)
- Outsiders, The (Dutch drum and bass duo)
- Outsiderz 4 Life
- Outspoken
- Outspoken (Hardcore, original band from 1990)
- Outspoken, We
- Outta Control (Canadian euro dance project)
- Outta Pocket (Bay Area Hardcore)
- Outtrigger
- Outwild
- Outwork
- Outwork feat. Gee, Mr.
- Outworld (American Progressive Metal Band)
- Ouvindo
- Ouvrard, Gaston (fils)
- Ouzo Bazooka
- Ov Hell
- Ov Lustra
- Ov Moros
- Ov Sulfur
- Ov Sulfur feat. Jones, Howard
- Ov Sulfur feat. Medina, Kyle & Schoolcraft, Lindsay
- Ov Sulfur feat. Taylor Barber
- Ov Sulfur feat. Terrible, Alex
- OV7
- Oval Opus
- Ovall
- Ovalle, Iván
- OVAN (Korean rapper)
- Ovations, The (US vocal group from New Jersey)
- OVCOCO
- OvDeth
- OVE (Indie-Pop Band from Hamburg, Germany)
- Ovejas Negras, Las
- Ovejas Negras, Las feat. Ñengo Flow
- Ovenden, Julian & McPhee, Katharine
- Ovens
- OVER ARM THROW
- Over Easy (American DJ/Producer Duo)
- Over It
- Over My Dead Body
- Over My Dead Name
- Over October (Filipino pop/alternative rock band)
- Over The Bridge
- Over the Moon (French pop duo)
- Over the Ocean (from New York, USA)
- Over the Rhine
- Over the Wall (Glasgow, Scotland)
- Over, Lary
- Over, Lary & Darell
- Over, Lary & Ñejo
- Over, Lary, Amenazzy & Farruko
- Overall, Kassa
- Overall, Kassa feat. Brown, Danny & Wiki
- Overall, Kassa feat. Croker, Theo
- Overall, Kassa feat. Hakim, Nick & Croker, Theo
- Overall, Kassa feat. Hoard, J.
- Overall, Kassa feat. Iyer, Vijay
- Overall, Kassa feat. Lil B, Shabazz Palaces & Francis and the Lights
- Overall, Kassa feat. Mvula, Laura & Francis and the Lights
- Overboard
- Overboard (a cappella group)
- Overcast (US metalcore band)