- O
- OO
- OO
- OOak
- OakObe
- ObeObs
- ObsOce
- OceOct
- OctOdd
- OddODE
- ODEOdu
- ODVOff
- OffOG
- OGOh
- OHOhm
- OhmOjo
- OjoOki
- OkiOla
- OlaOld
- OldOle
- OleOli
- OliOlo
- OloOma
- OmaOme
- OmeON
- ONOne
- OneONE
- ONEOne
- OneOnl
- OnlOnu
- OnwOpa
- OpaOph
- OphOR
- OrOrb
- OrbOrc
- OrcOre
- OreOri
- OriOrk
- OrkOrp
- OrpOrs
- Orsory
- OrzOsc
- OscOsl
- OslOst
- OstOti
- OtiOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOve
- OveOwe
- OweOxm
- OXOOzo
- OzoOZZ
- Observer (Shoegaze)
- Observer Drift
- Obsessed, The (doom metal music)
- Obsession (UK dance remakes for Almighty Records)
- Obsession (American metal)
- Obsessive (1990s techno/trance artist David Lübner)
- Obsessives, The
- Obsidia (Dubstep/Dubstyle/Drum & Bass/Electronic Producer from the UK)
- Obsidia & Boyinaband
- Obsidian Kingdom
- Obsidian Mind
- Obsidian Shell
- Obsidian Shrine
- Obsidian Tide
- Obsidian Tongue (US atmospheric black metal)
- Obsidiots
- Obsidious
- Obskür
- Obskür (Obskür)
- Obsolescence
- Obsolete Humanity (Belgian death/groove metal band)
- Obsolete Theory
- Obsoletos
- Obstetra (Grindcore from Spain)
- Obstrukt
- OBSYDIA (NIJISANJI EN VTuber group)
- Obtained Enslavement
- Obtest
- Obukuro, Nariaki
- Obús
- obylx
- Obywatel G.C.
- OC Hermo
- OC Saint
- OC Ska Kids
- OC Times (Barbershop Quartet)
- OC, Charlotte (Singer)
- Ocak, Arif Erdem
- Ocaklı, Erkan
- Öçal, Burhan & Trakya All Stars, The
- Ocampo, Pablo
- Ocaña, Chico
- Ocarina
- Ocasek, Ric
- Occams Laser
- Occas (new age)
- Occasional Dreams
- Occasionally Humans
- Occasionally, Jordan
- Occidens
- Occult Hand Order
- Occultation (US Doom Metal)
- Occults
- Occurrence (Experimental Electronic Pop Band from NYC)
- OCD (Philadelphia rap duo)
- Oceaán (Brussels-born Manchurian electronic music producer)
- Oceán (Czech electronic group)
- Ocean (US gospel rock band from the 1970s)
- Ocean (Swiss soft rock and folk rock band)
- Ocean (Polish Rock Band)
- Ocean Alley
- Ocean Blue, The (American indie pop)
- Ocean Chief
- Ocean Colour Scene
- Ocean Drive
- Ocean Drive feat. Oriska, DJ
- Ocean Flaws
- Ocean Floor (Northern UK alt-rock 4 piece)
- Ocean Grove (Australian nu metal band)
- Ocean Grove (United States)
- Ocean Grove feat. Dune Rats
- Ocean Grove feat. lil aaron
- Ocean Hills (Rock band from Los Angeles)
- Ocean Is Theory
- ocean jams
- Ocean Jet
- Ocean Kelly (Rapper, Legendary Icon)
- Ocean Music
- Ocean of Grief
- Ocean of Lotion
- Ocean Park Standoff
- Ocean Party, The
- Ocean Sleeper (Metalcore band)
- Ocean Tides
- Ocean Voyager
- Ocean Wings
- Ocean, Billy
- Ocean, Daniel (trance DJ & producer from Odessa, Ukraine)
- Ocean, Danny (Venezuelan singer, songwriter and producer, "Me rehúso"/"Baby I Won’t")
- Ocean, Danny & Dread Mar-I
