- O
- OO
- OO
- OO
- OOak
- OakObe
- ObeObr
- ObrOcc
- OccOce
- OceOct
- OctOdd
- OddODE
- ODEOdp
- OdrOfa
- OFBOff
- OffOge
- OgeOh
- OhOhm
- OhmOje
- OjeOKA
- OKAOku
- OkuOla
- OLAOld
- OldOle
- OleOli
- OliOli
- OliOls
- OlsOma
- OmaOme
- OmeOMN
- OmnOnc
- OncOne
- OneOne
- OneOne
- ONEOnk
- Onkono
- OnoOok
- OokOpe
- OpeOph
- OphOpu
- OpuOra
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- OrcOre
- OreOri
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- OrqOrt
- OrtOsa
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- OttOtu
- otuOur
- OurOut
- OutOut
- OutOuu
- OuvOve
- OveOvi
- OviOwe
- OweOxi
- OxiOzc
- Ozcozw
- OZwozz
- Obregón, Karen
- Obrero
- Obrint Pas
- OBS (German DJ duo)
- Obscene Eulogy (Canadian black metal)
- Obscenity (German death metal band)
- Obscenity Trial
- Obscura (technical death metal band from Munich, Germany)
- Obscura Qalma (Symphonic death metal from Venice, Italy)
- Obscura Religio
- Obscurcis Romancia
- Obscure (Bangladeshi band)
- Obscure Anachronism
- Obscure Disorder
- Obscure of Acacia
- Obscure Sphinx
- Obscure, The
- Obscurest Vinyl (AI generated music, uses various false pseudonyms)
- Obscurity (Swedish death metal band)
- Obscurity (black/Viking metal band from Germany)
- Obsecration (Greek death metal band)
- Obsequiae
- Observatory, The (US rock band from Athens, Georgia)
- Observatory, The (Singaporian space rock)
- Observe & Control
- Observer (Shoegaze)
- Observer Drift
- Obsessed, The (doom metal music)
- Obsession (UK dance remakes for Almighty Records)
- Obsession (New Haven, CT 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 Tide feat. LePond, Michael
- Obsidian Tide feat.LePond, Michael
- Obsidian Tongue (US atmospheric black metal)
- Obsidian Voice
- Obsidiots
- Obsidious
- Obskür (Dublin duo)
- Obskür (Obskür)
- Obskuros
- 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
- Obvious Creature
- Obviously
- obylx
- Obywatel G.C.
- OBZ (Dutch Group)
- OC Chris
- OC Hermo
- OC Osilliation (Zambian singer Siame O'Brien)
- OC Saint
- OC Ska Kids
- OC Times (Barbershop Quartet)
- OC Tolbert
- OC, Charlotte (Singer)
- Ocak, Arif Erdem
- Ocaklı, Erkan
- Öçal, Burhan & Tacuma, Jamaaladeen
- Öçal, Burhan & Trakya All Stars, The
- Öçal, Burhan & Trakya All Stars, The feat. Smadj
- Ocampo, Pablo
- Ocaña, Chico
- Ocarina
- Ocasek, Ric
- Ocaso (Hardcore deathcore band from Chile)
- Ocboyblau
- Occams Laser
- Occas (new age)
- Occasional Dreams
- Occasionally Humans
- Occasionally, Jordan
- Occidens
- Occult (Dutch thrash metal band)
