- O
- OO
- OO
- OO
- OOak
- OakOat
- OatObi
- ObiObs
- ObsOce
- OceOce
- OceOct
- OctOdd
- OddOde
- OdeODM
- OdmOer
- OerOff
- OffOff
- OffOGR
- OGROh
- ohOHM
- OHMOja
- OjaOka
- OkaOkt
- OktOLA
- OlaOld
- OldOle
- OleOli
- OliOli
- OliOll
- OllOLU
- OluOm
- OmOme
- OmeOmo
- OMOOna
- OOne
- OneOne
- OneOne
- oneOne
- ONFOnl
- Onl
- Oon
- OonOpe
- OpeOpi
- OpiOpu
- OpuOra
- OraOrb
- OrbOrc
- OrcOrd
- OrdOrg
- OrgOri
- OriOri
- OriOrm
- OrmOrp
- OrpOrr
- OrrOrt
- OrtOsb
- OsbOsc
- OscOsl
- OslOsT
- ote
- OteOtr
- OtrOtt
- OttOur
- OurOut
- OutOut
- OutOut
- OutOve
- OVEove
- oveOvs
- OVSOwi
- OWIOxl
- Oxl
- OzcOzu
- Ozuozz
- Octavian Winters
- OCTAVIO
- Octavio Garcia
- Octavio Mai (French electronic/alternative duo of Juliette Bazenet and Johan Putet)
- Octavio the Dweeb
- Octavus Lupus (Symphonic metal band from Lieusaint, Île-de-France)
- octi
- Octinomos
- OCTiV
- OCTiV feat. Celldweller
- Octo Octa
- October 31 (US Heavy Metal)
- October Burns Black
- October Country
- October Dogs
- October Drift
- October Ember
- October Ends
- October Fall (piano-fueled pop punk band)
- October Falls (Finnish atmospheric black metal)
- October File
- October Jimmy
- October Light
- October London
- October London feat. Snoop Dogg
- October Noir
- October People
- October Project
- October Rage
- October Rising
- October Sky
- October Tide
- October Tooth (Zachary Threlkeld)
- October, Jonny (NYC rapper)
- Octoberman (Canadian indie rock band)
- Octobre (rock band from Quebec)
- Ôctôctô
- OctoLab
- Octoploid
- Octoploid feat. Joutsen, Tomi
- Octoploid feat. Koivusaari, Tomi
- Octoploid feat. Kotamäki, Mikko
- Octopus (UK britpop group)
- Octopus (1970s German progressive rock group)
- Octopus (1970s Belgian pop band)
- Octopus (Progressive metal band from Chile)
- Octopus (1970s British psychedelic pop band)
- Octopus (1970s UK psychedelic rock band from Hatfield)
- Octopus Montage
- Octopus Project, The
- OCTPATH
- Octubre (spanish power-pop)
- Octubre Doce
- OCULA
- OCULA feat. LaRue, Phillip
- OCULA feat. Tailor
- Oculist, The
- Oculos (Death/Thrash Metal band from Turkey)
- Ocults
- Oczojebny, Jakub
- Oczojebny, Jakub feat. Kiti
- OD Band
- OD Bongo
- OD Kokemus
- OD404
- Oda (Norwegian pop singer)
- Oda (French stoner doom band)
- Oda, Hiroyuki pres. HanasoumenP
- Oda, Kaori (KAORI for Yuki Kajiura)
- Oda, Kazumasa
- Oda, Tetsurou
- Oda, Yuji
- Oda, Yuji
- ODAE
- Odani, Misako
- Odar (Bosnian Black Metal from Sarajevo)
- Odawas
- Odbicia, W Witrynach
- ODC (Modern Rock and Metal project created and led by Celia Do)
- ODC feat. SUN
- Odd (Norwegian singer/songwriter Odd Nordheim)
- Odd (Filipino post-rock band from Dumaguete)
- Odd Advantage, The (Ska band from Hemet, California)
- Odd Beholder (Swiss pop duo)
- Odd Børre
- Odd Chap
- Odd Chap & Lea, Emma
- Odd Chap & Lyre Le Temps
- Odd Chap & Rose, Octavia
- Odd Chap, Myers, Sarah
