...Of Celestial	Ukraine	Extreme Symphonic Metal	Active
...of Dream and Drama	Spain	Doom/Death Metal	Split-up
...of the Human Condition	Australia	Melodic Death/Gothic Metal	Split-up
...On the Night	Poland	Black/Death Metal	Split-up
O	Italy	Black Metal/Grindcore	Active
O	Finland	Raw Black Metal	Active
O Anjo Exterminador	Brazil	Industrial Metal/Death Metal	Split-up
O Oraculo de Asaradel	Brazil	Black/Doom Metal	Split-up
O'Cold Korns	Austria	Death Metal	Active
O, Majestic Winter	United States	Experimental 'Black' Metal	On hold
O-Nirik	France	Melodic Death/Thrash Metal	Active
O-Zone	France	Heavy Metal	Changed name
O.68	Germany	Doom Metal/Industrial	Active
O.A.	Japan	Heavy Metal	Active
O.B.E.Y.	United Kingdom	Drone Doom, Thrash Metal	Active
O.C.D.	France	Heavy Metal	Active
O.C.D.	United States	Thrash/Groove Metal	Unknown
O.D.	United States	Heavy Metal/Hard Rock	Active
O.D.O.	Italy	Thrash Metal	Changed name
o.d.r.a	Poland	Sludge Metal/Post-Hardcore	Active
O.H.	Bulgaria	Death/Thrash/Groove Metal	Active
O.H.D.	Netherlands	Death Metal/Grindcore	Split-up
O.I.D.	Italy	Thrash Metal	Split-up
O.L.D.	United States	Grindcore (early), Industrial/Avant-garde Metal (later)	Split-up
O.M.	Bolivia	Heavy Metal	Split-up
O.M.S.F.	United States	Power Metal	Split-up
O.Miserum.Mane	Spain	Doom/Death Metal	Split-up
O.R.B.	Canada	Progressive/Stoner Metal	Active
O.R.C.	United States	Black Metal, Doom Metal, Ambient	Active
O.R.D.A.	Italy	Thrash Metal	Split-up
O.S.F.	United States	Technical Death Metal	Unknown
O.T. Factor	United States	Thrash/Power Metal	Split-up
O.V.D.	Finland	Speed Metal	Changed name
O.X.	Russia	Heavy/Thrash Metal	Active
Oak	Sweden	Doom Metal	Active
Oak	Netherlands	Folk NS Black Metal	Split-up
Oak	United States	Death/Doom Metal	Active
Oak	Finland	Doom Metal	Active
Oak Coffin	United States	Black Metal	Split-up
Oak Roots	Italy	Folk Metal	Active
Oaken Throne	Argentina	Melodic Death, Viking Metal	Split-up
Oaken Tower	United States	Black Metal	Active
Oakenshield	Brazil	Pagan Metal	Split-up
Oakenshield	United Kingdom	Viking/Folk Metal	Active
Oakhelm	United States	Pagan Folk Black Metal	Active
Oaks	United States	Stoner Metal	Active
Oaks of Bethel	United States	Ambient Drone/Black Metal	Active
Oath	Canada	Folk/Black Metal	Active
Oath	Australia	Black Metal	On hold
Oath	Italy	Thrash/Speed Metal	Active
Oath	Switzerland	Death/Black Metal	Active
Oath	Spain	Heavy Metal	Active
Oath	Brazil	Black Metal	Active
Oath	Finland	Death/Thrash Metal	Split-up
Oath and Addiction	Germany	Avant-garde Black/Doom/Death Metal	Changed name
Oath of an Exile	United States	Metalcore/Melodic Death Metal	Active
Oath of Cirion	Finland	Symphonic/Black Metal	Split-up
Oath of Insanity	United States	Thrash Metal	Active
Oath of Woe	Denmark	Epic Doom Metal	Active
Oath to Vanquish	Lebanon	Technical Death Metal/Grindcore	On hold
Oath Witness	Mexico	Heavy/Progressive Metal	Unknown
Oathcult	Germany	Black Metal	Active
Oathean	Korea, South	Melodic Black/Death Metal	Active
Obduction	Slovenia	Melodic Death Metal (early), Progressive/Heavy Metal (mid), Alternative Metal/Rock (later)	Active
Obduction	Greece	Death Metal	Split-up
Obduktion	Greece	Death Metal	Split-up
Obduracy	Canada	Death Metal	Active
Obduracy	Sweden	Death Metal	Unknown
Obdurate Seduction	Australia	Gothic Metal with Thrash Influences	Changed name
Obdurated	France	Thrash Metal	Active
Obe	Italy	Thrash Metal	Active
Obeah	Netherlands	Death Metal	Active
Obed	Venezuela	Melodic Death Metal	Active
Obedience	Finland	Death Metal	Active
Obedient Chaos	Finland	Melodic Death Metal/Metalcore	Active
Obehag	Sweden	Black Metal	Active
Obeisance	United States	Thrash/Black Metal	Active
Obelisk	Ireland	Thrash Metal	Active
Obelisk	United States	Epic/Folk Metal	Split-up
Obelisk	United States	Black/Death Metal	Split-up
Obereit	Russia	Dark Metal	Active
Oberon	Norway	Folk/Black Metal	Split-up
Oberon	Sweden	Thrash/Death Metal	Changed name
Oberon	United States	Progressive Stoner Metal	Active
Oberon	Czech Republic	Thrash Metal/RAC	Unknown
Oberon	Canada	Death Metal (early), Thrash/Power Metal (later)	Split-up
Obertura	Venezuela	Death Metal	Split-up
Obertura	Ecuador	Death Metal	Active
Obertura	Mexico	Traditional Heavy Metal	Split-up
Obesity	Germany	Death/Thrash Metal	Split-up
Obey	Sweden	Death Metal/Grindcore/Thrash	Changed name
Obey	United Kingdom	Raw Black Metal	Split-up
Obey Bizar	United States	Post-Thrash/Groove Metal	Split-up
Obfuscate	United States	Black/Death Metal	Active
Obfuscate	Hungary	Death Metal	Active
Obfuscate Mass	Australia	Death Metal	Split-up
Obfuscation	Finland	Death Metal/Grindcore	Split-up
Obiat	United Kingdom	Stoner/Doom Metal	Active
Obidil	Slovenia	Progressive Heavy Metal	Active
Obire Mortem	Mexico	Melodic Death Metal	Active
Obire Pestis	United States	Black Metal	Split-up
Obispo Fornicado	Spain	Death Metal/Grindcore	Active
Obitania	Spain	Blackened pagan/Ambient	Active
Obito	Argentina	Black Metal	Active
Obitor	Colombia	Death Metal	Active
Obituary	United States	Death Metal	Active
Obitum	Argentina	Death Metal	Active
Obitus	Sweden	Black Metal	Active
Obius	United Kingdom	Progressive Metal	Unknown
Object of Aggression	United States	Death Metal/Metalcore	Active
Objective Zero	Australia	Brutal Death Metal	Changed name
Objector	France	Thrash/Death Metal	Split-up
Oblation	United States	Death Metal	Split-up
Oblech	Poland	Death Metal	Split-up
Oblidian	United States	Progressive/Groove Metal	Active
Obligatorisk Tortyr	Sweden	Death Metal/Grindcore	Active
Oblige	United States	Groove/Death Metal	Split-up
Oblique Rain	Portugal	Progressive Metal	Active
Oblique Visions	Malta	Doom Metal (early), Experimental Progressive Metal (2006-)	Active
Obliquity	United States	Death Metal	Active
Obliquity Inc.	United Kingdom	Progressive/Melodic Thrash Metal	Active
Obliteracao	Brazil	Grindcore	Active
Obliterate	Slovakia	Death Metal/Grindcore	Active
Obliterated	United States	Progressive Death Metal	Active
Obliteration	Norway	Death Metal	Active
Obliteration	United States	Death Metal	Changed name
Obliteration	Costa Rica	Death Metal	Split-up
Obliteration	United States	Death/Black Metal	Split-up
Obliteration	United Kingdom	Thrash/Heavy Metal	Split-up
Obliteration	Brazil	Thrash Metal	Split-up
Obliteration	Germany	Death Metal/Grindcore	Split-up
Obliteration X	United States	Death Metal	Active
Obliterator	Portugal	Heavy/Thrash Metal/Shred	Active
Obliterator	United States	Thrash Metal	Split-up
Obliterator	United States	Thrash/Power Metal	Split-up
Obliti Devoravit	United States	Black Metal	Active
Obliveion	United States	Heavy Metal	Split-up
Obliveon	Canada	Technical Death/Thrash Metal	Split-up
Oblivian Nightmare	Netherlands	Death/Thrash Metal	Changed name
Oblivio	Italy	Doom/Death Metal (early), Depressive Rock/Metal (later)	Active
Oblivion	Brazil	Heavy/Power Metal	Active
Oblivion	Germany	Progressive Metal	Changed name
Oblivion	Romania	Melodic Death/Thrash Metal	Split-up
Oblivion	Cyprus	Melodic Death/Thrash Metal	Active
Oblivion	Sweden	Melodic Death Metal	Active
Oblivion	Germany	Black Metal	Changed name
Oblivion	United States	Melodic Death Metal	Changed name
Oblivion	Germany	Thrash Metal	Split-up
Oblivion	United States	Power Metal	Active
Oblivion	Germany	Death/Doom Metal	Changed name
Oblivion	Sweden	Stoner Metal/Rock with Grunge influences	Active
Oblivion	Belgium	Doom Metal	Split-up
Oblivion	Colombia	Heavy/Thrash Metal	Changed name
Oblivion	United States	Thrash Metal	Split-up
Oblivion	France	Death Metal	Split-up
Oblivion	United States	Technical Death Metal	Active
Oblivion	Poland	Black Metal	Changed name
Oblivion	Croatia	Speed/Thrash Metal	Split-up
Oblivion	Poland	Death Metal	Active
Oblivion	Greece	Progressive Metal	Split-up
Oblivion	Spain	Black Metal	Unknown
Oblivion	United States	Thrash Metal	Active
Oblivion	Italy	Thrash Metal	Split-up
Oblivion	Spain	Thrash/Doom/Death Metal	Active
Oblivion	Sweden	Thrash Metal	Active
Oblivion	Poland	Melodic Death Metal	Changed name
Oblivion	Lebanon	Heavy Metal	Active
Oblivion	Germany	Heavy/Traditional Metal	Split-up
Oblivion	Canada	Thrash Metal	Changed name
Oblivion	United States	Thrash Metal	Split-up
Oblivion 999	Italy	Death/Thrash Metal	Active
Oblivion A.D.	United States	Heavy Metal, Rock	Split-up
Oblivion Awaits	Serbia	Symphonic Heavy Metal	Active
Oblivion Circle	Portugal	Gothic Metal	Active
Oblivion Echo	Greece	Atmospheric Black Metal	Active
Oblivion Knight	United States	Melodic Speed Metal	Active
Oblivion Machine	Russia	Industrial Death Metal	Active
Oblivion Myth	United States	Power/Progressive Metal	Active
Oblivion River	Greece	Melodic Death Metal	Active
Oblivion's Eye	Canada	Atmospheric/Progressive Death Metal	Active
Oblivion's Rising	Greece	Melodic Black/Death Metal	Active
Oblivione	Argentina	Thrash Metal	Split-up
Oblivionized	United Kingdom	Technical Brutal Death Metal/Grindcore	Active
Oblivious Enslavement	United States	Melodic Black/Death Metal	Split-up
Oblomov	Czech Republic	Black/Death Metal with Folk influences	Active
Oblong Box	United States	Death/Thrash/Heavy Metal	Active
Oblyvion	Italy	Death Metal	Active
Obnounce	Slovenia	Black/Death Metal	Active
Obnoxious	Germany	Power/Thrash Metal	Split-up
Obnoxious	France	Thrash/Death Metal/Deathcore	Active
Obnoxious	Sweden	Death Metal	Changed name
Obnoxious	Canada	Death Metal	Split-up
Obnoxiousness	Poland	Doom Metal	Changed name
Oboltred	Lithuania	Death Metal	Active
Obolus	United States	Black Metal	Active
Obor Setan	Indonesia	Progressive Black Metal	Active
Obrero	Sweden	Doom/Stoner Metal	Active
Obriotanya	Sweden	Black Metal	Split-up
Obruthion	Finland	Black Metal	Split-up
Obscence	Greece	Brutal Death Metal/Grind	Active
Obscene	Sweden	Death/Doom Metal	Split-up
Obscene	Finland	Death Metal/Grindcore	Changed name
Obscene	Sweden	Brutal Death Metal	Split-up
Obscene Crisis	Canada	Death Metal/Grindcore	Active
Obscene Eulogy	Canada	Death/Black Metal	On hold
Obscene Gesture	United States	Thrash Metal/Crossover	Active
Obscene Jester	United States	Power/Thrash Metal	Split-up
Obscenery	Netherlands	Black/Death Metal	On hold
Obscenity	Germany	Death Metal	Active
Obscenity	Italy	Death Metal	Changed name
Obsceno	Mexico	Death Metal/Goregrind	On hold
Obscenum	United States	Death Metal	Split-up
Obscenus	Portugal	Death/Doom Metal	Split-up
Obscenus	Luxembourg	Black Metal	Active
Obscura	Germany	Thrash/Death Metal	Active
Obscura	Sweden	Death Metal	Changed name
Obscura	Germany	Progressive/Technical Death Metal	Active
Obscura	Ecuador	Thrash/Death/Groove Metal	Active
Obscura Amentia	Italy	Black Metal	Active
Obscura Monotonia Animae	Italy	Ambient/Black Metal	Active
Obscura Nocte	Italy	Doom/Black Metal	Split-up
Obscura Nox Hibernis	Italy	Black Metal	Split-up
Obscura Religio	Germany	Melodic Black/Gothic Metal	Active
Obscura Symphonia	France	Black Metal	Split-up
Obscurant	Finland	Death Metal (early), Melodic Death Metal with Doom influences (later)	Split-up
Obscurarte	Italy	Black Metal	Active
Obscuration	Norway	Black Metal	Split-up
Obscuration	France	Gothic/Black Metal	Split-up
Obscuratum	Sweden	Black Metal	Active
Obscurcis Romancia	Canada	Symphonic Black Metal	Active
Obscure	France	Depressive Black Metal	Active
Obscure	Turkey	Black Metal	Active
Obscure	Austria	Death Metal/Grindcore	Active
Obscure	United Kingdom	Metalcore/Death Metal/Grindcore	Split-up
Obscure	Poland	Death Metal	Active
Obscure	Austria	Death Metal	Changed name
Obscure	Netherlands	Black Metal	Unknown
Obscure	France	Death Metal	Split-up
Obscure	Germany	Groove/Post-Thrash Metal	Split-up
Obscure	Germany	Death Metal	Split-up
Obscure	United States	Progressive Metal	Split-up
Obscure	Germany	Atmospheric Death Metal	Active
Obscure	Spain	Death Metal	Active
Obscure	Guatemala	Raw Black Metal	Unknown
Obscure	Norway	Heavy/Doom Metal	Active
Obscure	Germany	Thrash/Groove Metal	Split-up
Obscure 13	Germany	Death Metal	Split-up
Obscure Anachronism	Austria	Black Metal	Active
Obscure Death	Brazil	Death/Black Metal	Active
Obscure Devotion	Italy	Black Metal	Active
Obscure Disaster	Germany	Death Metal	Split-up
Obscure Dismay	Italy	Black Metal	Split-up
Obscure Divinity	Sweden	Death Metal	Split-up
Obscure Foret	France	Black Metal	Split-up
Obscure Infinity	Germany	Death Metal	Active
Obscure Infinity	Sweden	Death Metal	Split-up
Obscure Lupine Quietus	United Kingdom	Raw Black Metal	Active
Obscure Mind	Brazil	Black Metal	Active
Obscure Natus	Greece	Atmospheric Death/Doom Metal	Split-up
Obscure Oath	Germany	Death Metal	Active
Obscure Sphinx	Poland	Sludge/Doom Metal/Post-Rock	Active
Obscure Valley	Brazil	Pagan Black Metal	Active
Obscure Vortex	Germany	Black Metal	Split-up
Obscurecidos	Chile	Melodic Death/Thrash	Changed name
Obscured	Chile	Black Metal	Active
Obscured	Estonia	Atmospheric Death Metal	Split-up
Obscured	Sweden	Death Metal	Split-up
Obscured	Serbia	Death/Thrash Metal	Active
Obscured Introitu	Brazil	Progressive Death Metal/Fusion	Split-up
Obscured Secretions	United States	Brutal Death Metal	Active
ObscureDream	China	Black Metal	Active
Obscureism	United States	Black Metal	Split-up
Obscuri Tronos	Brazil	Black Metal	On hold
Obscuria	Germany	Melodic Death/Thrash Metal	Active
Obscuritas	Germany	Death Metal	Split-up
Obscuritas Est Imperium	Germany	Black Metal	Unknown
Obscuritatem	Italy	Funeral Doom/Black Metal	On hold
Obscurity	Germany	Pagan/Viking Metal	Active
Obscurity	United States	Thrash Metal	Split-up
Obscurity	Sweden	Death Metal	Split-up
Obscurity	Turkey	Death Metal/Grindcore	Split-up
Obscurity	Slovenia	Thrash/Dark Metal	Split-up
Obscurity	United States	Death Metal	Split-up
Obscurity	Germany	Melodic Death Metal	Split-up
Obscurity	Sweden	Death Metal	Active
Obscurity	Germany	Death Metal	Split-up
Obscurity	Greece	Black/Death Metal	Split-up
Obscurity	Portugal	Gothic/Doom Metal	Changed name
Obscurity Tears	Brazil	Doom Metal	Active
Obscuro	Sweden	Raw Black Metal	Active
Obscuro Austral	Chile	Black Metal with thrash influences	On hold
Obscuro Corvus	Czech Republic	Melodic Death/Doom/Thrash Metal	Active
Obscuro Impeto	Brazil	Black Metal	Active
Obscurum	United States	Black Metal	Active
Obscurum	Czech Republic	Death Metal	Active
Obscurum	Belgium	Black Metal	Split-up
Obscurum Malum	Italy	Black Metal	Active
Obscurum Noctis	Romania	Black Metal	Split-up
Obscurus	Germany	Black/Death Metal	Active
Obscurus	Argentina	Melodic/Atmospheric Black Metal	Unknown
Obscurus	Brazil	Black Metal	Split-up
Obscurus Advocam	France	Black Metal	Split-up
Obscurys	Germany	Black/Death Metal/Grindcore	Active
Obscvrii Lvnae	Portugal	Black Metal	Split-up
Obsecration	Greece	Death Metal	Active
Obsek	Canada	Death Metal/Metalcore	Active
Obsequiae	United States	Melodic Dark Metal	Active
Obsequies	Singapore	Death Metal	Split-up
Obsequies	Netherlands	Black/Doom Metal	Split-up
Obsequies	Cyprus	Black Metal	Unknown
Obsequy	United States	Progressive/Death Metal	Changed name
Observant	Finland	Melodic Death Metal	Active
Observing the Obscenery	Canada	Black/Heavy Metal/Avant-garde	Active
Obsesion Compulsiva	Spain	Industrial/Death Metal	Changed name
Obsessed	Germany	Black Metal	Split-up
Obsessed	Finland	Thrash Metal	Active
Obsessed by Seth	Russia	Brutal Death Metal	Active
Obsessed Mord	Poland	Death Metal	Split-up
Obsession	Argentina	Heavy Metal/Hard Rock	Active
Obsession	Finland	Heavy/Gothic Metal	Unknown
Obsession	United States	Heavy/Power Metal	Active
Obsessive Art	Finland	Dark Metal	Split-up
Obsessment	Czech Republic	Death Metal	Active
Obsessor	Brazil	Death Metal	Active
Obsessor	United States	Thrash Metal/Crossover/Punk	Active
Obsessor	Germany	Black/Thrash Metal	Active
Obsessos	Brazil	Death/Thrash Metal	Split-up
Obsidia	Austria	Gothic Metal	Active
Obsidian	Germany	Black Metal	Split-up
Obsidian	United States	Black/Death/Thrash Metal	Changed name
Obsidian	United Kingdom	Death Metal	Split-up
Obsidian	Netherlands	Progressive Death Metal	Split-up
Obsidian	Belgium	Heavy Metal	Split-up
Obsidian	United States	Industrial Death Metal	Active
Obsidian Aspect	Australia	Death Metal	Active
Obsidian Chamber	Austria	Symphonic Black/Death Metal	Active
Obsidian Flow	United States	Death Metal/Experimental	Active
Obsidian Forest	Australia	Black Metal	Active
Obsidian Gate	Germany	Symphonic Black Metal	Active
Obsidian Halo	United States	Death/Thrash Metal	Split-up
Obsidian Kingdom	Spain	Experimental Black/Death	Active
Obsidian Reign	Canada	Progressive/Traditional Metal	Split-up
Obsidian Sea	Bulgaria	Doom Metal	Active
Obsidian Shell	Hungary	Gothic Metal	Active
Obsidian Throne	United States	Melodic Death Metal	Active
Obsidian Tongue	United States	Atmospheric Black Metal	Active
Obsidieth	Australia	Symphonic Melodic Death/Black Metal	Active
Obsidio	Italy	Symphonic Black/Death Metal	Split-up
Obsidion	Ireland	Progressive Metal	Changed name
Obsidivm Spirti	Italy	Black Metal	Changed name
Obsin	Brazil	Heavy Metal	Active
Obskene Sonare	Austria	Black Metal	Split-up
Obskur	Germany	Black Metal	Active
Obskur	Canada	Heavy/Thrash Metal	Active
Obskure	Brazil	Melodic Death Metal	Active
Obskure Torture	Denmark	Black/Death/Doom Metal	Unknown
Obskurum	United States	Black Metal	Changed name
Obsolete	Malaysia	Death Metal	On hold
Obsolete Tomorrow	United Kingdom	Progressive Death Metal	Active
Obsta	United States	Death/Black Metal	Active
Obstetrical Palsy	Kazakhstan	Brutal Death Metal/Grind	Split-up
Obstinacy	Turkey	Melodic/Progressive Death Metal	Active
Obstinacy	Germany	Death Metal	Active
Obstinate	Indonesia	Metalcore/Deathcore	Active
Obstination	United States	Doom Metal	Changed name
Obstinato	Chile	Heavy Metal	Active
Obstruction	Hungary	Heavy Metal	Active
Obstruction	Germany	Death Metal	Split-up
Obstruktor	United States	Death/Thrash Metal	Split-up
Obstruo	United States	Black Metal	Split-up
Obstsalat	Germany	Heavy/Thrash Metal	Split-up
Obsydian	United Kingdom	Death Metal	Active
Obsydian	Canada	Blackened Death Metal	Active
Obsydian Tears	United Kingdom	Thrash/Groove Metal	Active
Obszon Geschopf	France	Industrial/Electronica/EBM (early), Industrial Thrash Metal (later)	Active
Obtain	France	Doom/Death Metal	Split-up
Obtain Pain	Denmark	Thrash/Death Metal	Active
Obtained Enslavement	Norway	Death Metal (early), Symphonic Black Metal (late)	Split-up
Obtenebratum	France	Black/Thrash Metal	Split-up
Obtenebris	Canada	Melodic Death Metal	Split-up
Obtest	Lithuania	Pagan/Black Metal (early) - Pagan/Heavy Metal (later)	Active
Obtruncation	Netherlands	Death Metal	Active
Obtrusive Mode	United States	Progressive/Groove/Industrial Metal	Split-up
Obturador	Argentina	Groove Metal	Split-up
Obtuse	Netherlands	Brutal Death Metal/Grindcore	Active
Obus	Spain	Heavy Metal/Hard Rock	Active
Obzidian	United Kingdom	Thrash/Progressive Metal	Active
Obled	Poland	Black Metal	Active
Ocanthus	United States	Gothic/Melodic Doom Metal	Unknown
Occams Razor	Canada	Progressive Power Metal	Split-up
Occasion	Netherlands	Heavy Metal/Hard Rock	Active
Occasus	Italy	Black Metal	Split-up
Occasus	Chile	Black Metal	Active
Occasus	United States	Groove Metal	Active
Occidens	Chile	Black/Death Metal	Active
Occisas	Venezuela	Death Metal/Grindcore/Industrial	Active
Occision	United States	Black/Death/Thrash Metal	Active
Occision	United States	Experimental Death Metal/Grindcore	Active
Occisionis	Costa Rica	Thrash Death Metal	Active
Occiso	Chile	Grindcore/Death Metal	Active
Occisor	Colombia	Death Metal	Active
Occisor	Canada	Death Metal	Split-up
Occitania	Spain	Heavy Metal	Active
Occrah	Sweden	Death Metal	Split-up
Occult	Chile	Black/Thrash Metal	Active
Occult	United States	Thrash/Black Metal	Split-up
Occult	Netherlands	Black/Thrash Metal	Changed name
Occult	France	Death Metal	Split-up
Occult Astral	Finland	Black Metal	Unknown
Occult Corpse	Spain	Black Metal	Active
Occult Crypt	Germany	Black/Death Metal	Active
Occult Crypts	Canada	Black Metal	Changed name
Occult Garden	Brazil	Atmospheric Doom/Death Metal	Active
Occult God	Brazil	Melodic Death Metal	Active
Occult Lore	Puerto Rico	Folk/Black Metal	Active
Occult Vomit	France	Raw Black/Thrash Metal	Active
Occult War	Slovakia	Black Metal	Unknown
Occulta	France	Black Metal	Changed name
Occulta	Romania	Raw Black Metal	Split-up
Occulta Struttura	Italy	Raw Black Metal, Dark Ambient	Active
Occultation	United States	Doom Metal/Progressive Rock	Active
Occultism	Puerto Rico	Blackened Death Metal	Split-up
Occultist	United States	Blackened Crust/Death/Thrash Metal	Active
Occultum Lapidem	Spain	Black Metal	Active
Occultus	France	Black Metal	Split-up
Occultus	Colombia	Melodic Black Metal	Active
Occulus	Canada	Black Metal	Active
Occulus	Germany	Melodic Death/Thrash Metal with Modern Rock elements	Active
Occurrence	Germany	Melodic Metal	Split-up
Occurrence	Germany	Death Metal	Split-up
Occvlta	Germany	Doom/Black Metal	Active
Ocean	United States	Sludge/Doom Metal	Active
Ocean Bed	Germany	Progressive Metal/Rock	Active
Ocean Chief	Sweden	Stoner/Doom Metal	Active
Ocean Machine	Canada	Progressive Metal	Split-up
Ocean of Zero	Australia	Death Metal	Active
Ocean Soul	Brazil	Power Metal	Active
Oceana	Italy	Gothic/Doom/Death Metal	Split-up
Oceano de Sangre	Argentina	Progressive Power Metal	Active
Oceans Afire	United States	Melodic Death Metal	Split-up
Oceans of Night	United States	Progressive Rock/Metal	Active
Oceans of Sadness	Belgium	Death/Black/Gothic Metal	Split-up
Oceans of Time	Norway	Progressive Power Metal	Active
Oceanspawn	United States	Death Metal	Changed name
Oceanus	United Kingdom	Atmospheric Extreme Metal	Active
Oceanus Procellarum	Ecuador	Black Metal/Ambient	Active
Ocelot	Czech Republic	Power/Speed Metal	Active
Ocoai	United States	Progressive/Sludge Metal	Split-up
Oconnor	Argentina	Heavy Metal (early), Hard Rock (later)	Active
Ocquityn	Germany	Progressive Metal	Split-up
Octagon	Colombia	Experimental Black Metal	Split-up
Octagon	United States	Black/Thrash Metal	Active
Octagon	Netherlands	Doom Metal	Split-up
Octagon	Poland	Death Metal	Unknown
Octagone	Czech Republic	Industrial Death Metal	Active
Octagram	Chile	Black Metal	Active
Octanic	Australia	Melodic Death/Groove Metal	Active
Octave	Italy	Crossover / Alternative Metal (early), Progressive Metal (later)	Active
Octavia	Norway	Gothic Metal	Changed name
Octavia Sperati	Norway	Gothic Metal with Doom influences	On hold
Octinomos	Sweden	Black Metal	Active
Octo Hora	Germany	Heavy Metal	Split-up
October	United Kingdom	Black Metal/Dark Ambient	Active
October	United States	Thrash/Groove Metal	Split-up
October 31	United States	Traditional Heavy Metal	Active
October Falls	Finland	Folk/Ambient, Dark Metal	Active
October Flame	United States	Black Metal/Ambient	Active
October Nightshade	Finland	Melodic Death/Doom Metal	Active
October Rust	Italy	Progressive Melodic Death Metal	Unknown
October Thorns	United States	Progressive/Death Metal	Split-up
October Tide	Sweden	Melodic Doom/Death Metal	Active
October's End	United States	Progressive Death Metal	Unknown
Octobers Fate	United States	Symphonic Metal	Active
Octobre	Canada	Oi!/Black Metal	Changed name
Octopus	Chile	Progressive Rock/Metal	Active
Octopus Triangle	United States	Progressive Metal/Rock	Active
Octoria	Germany	Black Metal	Split-up
Octum	Saudi Arabia	Thrash Metal	Active
Ocularis Infernum	Mexico	Black Metal	Active
Ocularis Infernum	Latvia	Melodic Black Metal	Active
Ocultan	Brazil	Black/Death Metal	Active
Ocultismo Eterno	Brazil	Black Metal	Active
Ocultus Sathanas	Brazil	Raw Black Metal	Active
Oculus	Chile	Black Metal	Active
Oculus Infernum	Italy	Black Metal	Split-up
Od'Sahe	Russia	Death/Black Metal	Active
Odal	France	Black Metal	Changed name
Odal	Germany	Pagan Black Metal	Active
Odal Rune	Belgium	NS Black Metal/Dark Ambient	Split-up
Odane	France	Progressive Metal	Split-up
Odar	Bosnia and Herzegovina	Black Metal	Active
Odd Crew	Bulgaria	Groove/Alternative Metal	Active
Odd Dimension	Italy	Progressive Metal	Active
Odd Goo	Germany	Atmospheric Gothic/Death Metal	Changed name
Odd Heathenish	Spain	Death Metal	Active
Odd Inertia	France	Deathcore	Split-up
Odd Logic	United States	Progressive Metal	Active
Odd Melody	Brazil	Thrash Metal	Split-up
Oddameatr	United States	Thrash/Progressive Metal	Split-up
Oddech Buntownika	Poland	Heavy/Thrash Metal	Split-up
Oddity	Mexico	Death Metal	Active
Oddium	Brazil	Thrash Metal	Active
Oddland	Finland	Progressive Metal/Rock	Active
Oddmongers	France	Thrash Metal	Split-up
Odds	Italy	Heavy Metal/Hard Rock	Split-up
Odds	France	Melodic Death Metal	Active
Odds N'Sods	Hungary	Thrash Metal	Split-up
Oddskabbcatz	Sweden	Black Metal	Unknown
Ode	Netherlands	Black Metal	Active
Ode Odium	Portugal	Gothic Metal	Split-up
Ode of Eternity	United Kingdom	Gothic Metal	Split-up
Ode to Decay	France	Black/Death Metal	Active
Odeiross	Mexico	Progressive/Heavy Metal	Active
Odem	Russia	Black/Death Metal	Active
Odem Arcarum	Germany	Black Metal	Active
oden	Sweden	Folk/Black Metal	Active
Oden's Raven	Germany	Viking/Melodic Death Metal	Unknown
Odenwrath	Sweden	Death/Viking Metal	Active
Odeon	Argentina	Thrash Metal	Unknown
Odeon	Germany	Black Metal	Active
Odes of Ecstasy	Greece	Symphonic Death Metal (early), Gothic Metal (later)	Active
Odessa	United States	Black Metal	Active
Odeum	Sweden	Death Metal	Split-up
Odhinn	Sweden	Viking Metal	Active
Odi Profanum Vulgus	Poland	Death/Black Metal	Active
Odica	Ecuador	Heavy Metal	Active
Odin	United States	Heavy Metal	On hold
Odin's Court	United States	Progressive Metal	Active
Odin's Eye	Sweden	Folk/Power Metal	Active
Odin's Hammer	Germany	Traditional Heavy Metal	Split-up
Odin's Law	Canada	RAC/Thrash Metal	Split-up
Odinfist	Canada	Power/Thrash Metal	Active
Odinn	Iceland	Death Metal	Active
Odins Court	Greece	Raw Pagan Black Metal	Active
Odins Forest	United States	Melodic Black Metal	On hold
Odio	Bolivia	Death/Thrash Metal	Split-up
Odio	Brazil	Thrash Metal	Active
Odio Vestri	Russia	Funeral Doom Metal/Dark Ambient	Active
Odios	Germany	Black Metal	Split-up
Odious	Germany	Death/Thrash Metal	Split-up
Odious	Egypt	Melodic Black Metal	Active
Odious Mortem	United States	Technical Brutal Death Metal	Active
Odious Sanction	United States	Death Metal/Hardcore	Active
Odisea	Argentina	Traditional Heavy Metal	Active
Odisea	Argentina	Heavy Metal	Changed name
Odisea	Cuba	Progressive Metal	Active
Odisseia	Brazil	Heavy Metal	Active
Oditeohr	France	Symphonic Black Metal	Active
Odium	Colombia	Black Metal	Split-up
Odium	United States	Death Metal	Split-up
Odium	Germany	Thrash/Power Metal	Active
Odium	Canada	Melodic Death Metal	Active
Odium	Sweden	Industrial/Death Metal	Active
Odium	Sweden	Death metal	Split-up
Odium	Greece	Death/Thrash Metal	Split-up
Odium	Poland	Death/Thrash Metal	Split-up
Odium	United States	Heavy/Thrash Metal	On hold
Odium	Poland	Progressive Death/Thrash/Gothic Metal	Split-up
Odium	France	Black Metal	Active
Odium	Russia	Melodic Doom/Death Metal	Changed name
Odium	Norway	Symphonic Black Metal	On hold
Odium	Russia	Black Metal/Ambient	Unknown
Odium	Canada	Death Metal	On hold
Odium	Russia	Death Metal (early), Progressive Metal (later)	Unknown
Odium	Bulgaria	Death Metal	Split-up
Odium	United Kingdom	Black Metal	Active
Odium Diabolicum	France	Black Metal	On hold
Odium Hominum	Brazil	Black/Death Metal	Active
Odium Immortalis	Germany	Melodic Black Metal	Split-up
Odium Inc.	Serbia	Melodic Death Metal	Split-up
Odium Inc.	United States	Heavy / Thrash Metal	Split-up
Odium Incarnate	United Kingdom	Death Metal	Changed name
Odium Malum	Bosnia and Herzegovina	Black Metal	Active
Odium Perpetuum	Portugal	Black Metal	Active
Odiusembowel	New Zealand	Brutal Death Metal/Grindcore	Active
Odo'Sha	Venezuela	Black/Folk Metal	Active
Odor Mortis	Russia	Black Metal	Split-up
Odpad	Czech Republic	Thrash Metal	Split-up
Odraedir	Czech Republic	Pagan/Folk Metal	Active
Odroerir	Germany	Folk Metal	Active
Odrum	Chile	Black Metal	Split-up
Odum	France	Progressive Death Metal	Active
Odyn's Nocturnal North	Kyrgyzstan	Black Metal	Split-up
Odyssea	Italy	Power Metal	Split-up
Odyssey	Spain	Progressive Metal	Active
Odyssey	Sweden	Progressive Metal	Active
Odyssey	Pakistan	Progressive/Power Metal	Active
Odyssey	South Africa	Heavy Metal	Split-up
Odyssey	United States	Progressive Metal	Active
Odyssey	United States	Thrash Metal	Active
Odyssey	France	Melodic Metal	Active
Odyssey Dawn	United States	Thrash/Power Metal	Active
Odz Manouk	United States	Black Metal	Active
Oerjgrinder	Belgium	Grindcore/Brutal Death Metal	Active
Oes Galliath	France	Black Metal	Active
Oestre	France	Post-Thrash/Industrial Metal	Active
Of Aeons	United States	Blackened Death Metal	Unknown
Of Agony and of Death	United States	Drone Black Metal / Ambient	Active
Of Angels and Gravediggers	United States	Death Metal/Hardcore	Split-up
Of Antiquity	United States	Death Metal	Active
Of Brutality and Grace	United Arab Emirates	Thrash/Groove Metal	Split-up
Of Buried Hopes	Belarus	Death Metal/Metalcore	Active
Of Darkness	Spain	Funeral Doom Metal	Active
Of Darksome Origin	Germany	Death Metal with Black/Gothic elements	Split-up
Of Death I Speak	United States	Death Metal	Active
Of Dream and Drama	Mexico	Death/Black Metal	Active
Of Dreams and Madness	United States	Progressive Metal	Active
Of Dying Dreams	United States	Heavy/Progressive/Groove Metal	Split-up
Of Fallen Crosses	United States	Experimental Black/Death Metal	Active
Of Forsaken Divinity	United States	Experimental Ambient Black Metal	Active
Of Grator	Australia	NS Black Metal	Active
Of Grief Everlasting	Australia	Doom/Death Metal	Split-up
Of Hatred	United States	Melodic Death/Thrash/Metalcore	Active
Of Human Bondage	Canada	Black Metal	Active
Of Humanity's Demise	Sweden	Deathcore	Active
Of Infinity	United States	Gothic Metal	Unknown
Of Mara	United Kingdom	Black Metal	Split-up
Of Oak	United States	Black/Folk Metal	Active
Of Parting Words	United States	Metalcore/Grindcore/Death Metal	Split-up
Of Raven & Ruins	United States	Melodic Death Metal	Active
Of Rytes	Germany	Thrash Metal	Split-up
Of Spire & Throne	United Kingdom	Doom Metal	Active
Of the Archaengel	Brazil	Melodic Dark Metal	Active
Of the Dead	United States	Doom/Death Metal	Active
Of the Fallen	United States	Symphonic Black Metal	Changed name
Of the Gods	United States	Groove Metal	Active
Of the Son	United States	Groove Metal/Metalcore	Split-up
Of the Wand & the Moon	Denmark	Neofolk	Active
Of Trees and Orchids	Germany	Progressive Death Metal	Changed name
Of Wrath and Ruin	United States	Progressive Metal	Active
Of Your Funeral	Finland	Gothic Metal	Active
OfDoom	Finland	Black/Death Metal	Split-up
Ofensiva	Spain	Crossover	Split-up
Oferd	Sweden	Black Metal	On hold
Ofermod	Sweden	Black Metal	Active
Off	Korea, South	Melodic Death Metal (early), Brutal Death Metal (later)	Active
Off the Wall	United States	Thrash Metal	Split-up
Off With Her Head	United States	Death Metal/Metalcore	Split-up
Offal	Brazil	Death Metal	Active
Offal Stench	New Zealand	Brutal Death Metal/Goregrind	Active
Offallectomy	Australia	Death Metal	Active
Offalmincer	Russia	Brutal Death Metal	Active
Offbach	Mexico	Melodic Heavy Metal	Unknown
Offence	Poland	Death Metal	Active
Offender	United States	Heavy/Traditional/Power Metal	Split-up
Offender	Italy	Black/Thrash Metal	Active
Offending	France	Brutal Death Metal	Active
Offense	Spain	Doom/Death Metal, Gothic Metal/Rock (Absence)	Active
Offensive	Japan	Death/Thrash Metal	Split-up
Offensor	Peru	Black/Death Metal	Active
Offerblod	Sweden	'Black' Metal	Active
Offering	Switzerland	Death Metal	Split-up
Offering	Finland	Funeral Doom Metal	Active
Offerings	Iceland	Death/Black Metal	Active
Offerkult	Denmark	Black Metal	Active
Offertorium	Moldova	Gothic/Progressive Metal	Split-up
Offertorium	Brazil	Black Metal	Active
Official Denial	United States	Heavy Metal	Split-up
Officium Triste	Netherlands	Death/Doom Metal	Active
Officum	Germany	Doom/Death/Black Metal	Split-up
Offset	Austria	Death Metal	Split-up
Offtall	Poland	Heavy Metal	Split-up
Offtopic	Spain	Heavy Metal	Active
Ofghost	Finland	Industrial Black/Death Metal	Active
Ofhisownhand	United States	Stoner/Sludge/Doom Metal	Split-up
OfO Am	France	Stoner Metal	Active
Ofring	Denmark	Black/Death Metal	Unknown
Ofryskje	Norway	Black Metal	Split-up
Ofsoski	Australia	Progressive Metal	Active
Og Tegnet	United States	Black Metal	Active
Ogdru Jahad	Denmark	Black/Death Metal	Active
Ogen	Italy	Atmospheric Black Metal	Active
Ogilt	Russia	Raw/Atmospheric Black Metal	Active
Ogmias	Czech Republic	Pagan Black Metal	Split-up
Ogmios	France	Black Metal/Ambient	Active
Ogotay	Poland	Death Metal	Active
Ogre	Ireland	Brutal Death Metal	Split-up
Ogre	Italy	Death Metal	Active
Ogre	United States	Doom Metal/Hard Rock	Active
Ogre	Japan	Death/Thrash Metal / Metalcore	Active
Ogre Upstairs	United States	Progressive Thrash Metal	Active
Ogress	Belgium	Thrash Metal	Active
Ogressa	United States	Stoner Metal	Active
Ogudaktig Seger	Colombia	Black Metal	Active
Oh Shit They're Going to Kill Us	United States	Thrash Metal/Crossover	Active
Ohavne zvuky	Czech Republic	Black Metal/Metalcore	Active
Ohmsapien	Philippines	Heavy Metal	Active
Ohrb	Brazil	Death / Thrash Metal	Split-up
Ohron	France	Pagan Black Metal	Unknown
Ohtar	Poland	Black Metal	Split-up
Ohura Mazdo	Japan	Black Metal	Split-up
Ohvrikivi	Estonia	Black Metal	Active
Oidhehe Baaltinne	Belgium	Black/Death Metal	Active
Oil	United States	Thrash Metal	Split-up
Oil Carter	France	Stoner/Thrash Metal	Active
Oizys	Australia	Black Metal	Active
Ojciec Dyktator	Poland	Grindcore	Active
Ojos Negros	Argentina	Thrash Metal	Active
Oker	Spain	Heavy Metal	Active
Okera	Australia	Melodic Death/Doom Metal	Active
Okketaehm	United States	Raw Black Metal	Active
Okkulta	Sweden	Heavy Metal	Active
Okkultokrati	Norway	Black Metal/Hardcore Punk	Active
Okkultum Magnificentia	Italy	Black Metal	Active
Okkultum Threat	Turkey	Black Metal	Split-up
Okosu	United States	Death Metal	Active
Okrozom	Czech Republic	Gothic/Heavy Metal	Active
Oksanat	Serbia	Black Metal	Active
Oksennus	Finland	Death Metal	Active
Oksymoron	Russia	Melodic Black/Death Metal	Split-up
Oktagon	Russia	Gothic Metal	Split-up
Oktober	United States	Thrash Metal	Split-up
Oktober	United States	Black Metal	Split-up
Oktopod	France	Death Metal/Grindcore	Split-up
Oktor	Poland	Funeral Doom Metal	Active
Okular	Norway	Melodic Progressive Death Metal	Active
Okult	France	Black Metal	Active
Okulus Diaboli	Belarus	Black Metal	Active
Ol Sonuf	United States	Symphonic Black Metal	Active
Ol' Scratch	United States	Sludge/Stoner/Doom Metal	Split-up
Olam Ein Sof	Brazil	Acoustic/Neo Folk Metal	Active
Olbaid	Spain	Thrash/Heavy Metal/Crossover	Split-up
Olc Sinnsir	France	Black Metal	Split-up
Old	Czech Republic	Thrash Metal	Active
Old	Germany	Black/Thrash Metal	On hold
Old Betrayer	Colombia	Black Metal	Active
Old Black	France	Black Metal	Active
Old Black Eternity	Ecuador	Black Metal	Active
Old Black Majestic	Colombia	Raw Black Metal	Active
Old Blood	Spain	Black Metal	Active
Old Bones	Sweden	Black Metal	Active
Old Castles Massacre	Sri Lanka	Brutal Death Metal	Active
Old Cemetery	Canada	Black/Doom Metal	Split-up
Old Corpse Road	United Kingdom	Black/Folk Metal	Active
Old Crow Cry	Brazil	Folk/Black Metal	Active
Old Dominion	Hungary	Black Metal	Split-up
Old Force	Chile	Thrash Metal	Active
Old Forest	United Kingdom	Black Metal	Active
Old Funeral	Norway	Death Metal	Split-up
Old Goat	United States	Black Metal	Split-up
Old Grandad	United States	Psychedelic Stoner/Death Metal	Split-up
Old Head	United States	Heavy/Thrash Metal/Hard Rock	Active
Old Kingdom	Mexico	Black Metal	Active
Old Legacy	Slovakia	Black Metal	Split-up
Old Legend	Italy	Death Metal (early), Black/Death Metal (later)	Active
Old Legend	France	Doom/Heavy/Thrash Metal	Split-up
Old Maid	United Kingdom	Death/Thrash Metal	Active
Old Man Gloom	United States	Sludge Metal, Ambient/Noise	Active
Old Man Lizard	United Kingdom	Stoner/Sludge Metal	Active
Old Man's Child	Norway	Melodic Black Metal	Active
Old Mayor	United Kingdom	Sludge/Doom Metal	Active
Old Memories	Norway	Symphonic Death Metal	Active
Old Morgul	Finland	Black Metal	Split-up
Old Oak	Sweden	Black Metal	Active
Old One	United States	Stoner/Doom Metal	Active
Old Pagan	Germany	Black/Thrash Metal	Active
Old Path	United States	Black Metal/Dark Ambient	Split-up
Old Razor	Russia	Black/Thrash Metal	Active
Old Ritual	Italy	Black Metal	Active
Old Roger	France	Death Metal	Split-up
Old Season	Ireland	Epic/Atmospheric Heavy Metal	Active
Old Serpent	United States	Black Metal	Active
Old Serpent	United States	Black Metal	Unknown
Old Serpents	Peru	Death/Black Metal	Active
Old Silver Key	Ukraine	Post-Rock/Shoegaze	Active
Old Sorcery	Portugal	Death/Doom Metal	Active
Old Throne	Brazil	Black Metal	Active
Old Throne	Mexico	Black Metal	Active
Old Tree	Australia	Black/Doom Metal	Active
Old Wainds	Russia	Black Metal	Active
Old Wolves	United States	Black Metal	Active
Old Words New	Norway	Progressive Death/Doom Metal	Unknown
Old Yron	Italy	Heavy Metal	On hold
Oldblood	Slovakia	Black/Thrash Metal, Black 'n' Roll	On hold
Olde Crone	United Kingdom	Stoner/Doom Metal	Split-up
Olde Growth	United States	Stoner/Sludge Metal	Active
Older Hammer	Finland	Black Metal	Split-up
Older North	United States	Viking Metal	Split-up
Oldgoblin	Italy	Black/Folk Metal	Active
Oldods	Sweden	Death Metal	Active
Oldskull	Venezuela	Thrash Metal	Active
Oldskull	France	Death Metal	Active
Oldwitch	Croatia	Doom Metal	Unknown
Olemus	Austria	Death/Black/Gothic Metal	Active
Olga	United States	Black Metal	Split-up
Olhrimnir	Finland	Folk Metal	Active
Oligarquia	Brazil	Death Metal	Active
Olive	Syria	Atmospheric Doom Metal	Split-up
Oliver Gerke	Germany	Heavy/Thrash/Black Metal/Hard Rock/Country	Active
Oliver Magnum	United States	Power/Speed Metal	Split-up
Oliver Weers	Denmark	Heavy Metal/Hard Rock	Active
Oliver/Dawson Saxon	United Kingdom	Heavy Metal	Active
Olocausto	Italy	Death Metal/Grindcore	Active
Olog-Hai	Finland	Black Metal	Split-up
Olorin	United States	Doom Metal	Active
Oltretomba	Italy	Black Metal	Active
Oltued	Sweden	Progressive Death/Groove Metal	Active
Olum	Turkey	Depressive Black Metal/Ambient	Active
Olum D?s?	Turkey	Death Metal/Grindcore	Split-up
Olvido	Spain	Melodic Dark Metal	Active
Olympos Mons	Finland	Power Metal	Split-up
Olyphant	United States	Heavy Metal	Active
Om	United States	Stoner/Doom Metal	Active
Om Mani	France	Experimental/Progressive Metal	Active
Omainen	France	Power Metal	Active
Omas Kojas	Estonia	Heavy Metal	Split-up
Omasum	Spain	Black Metal	Split-up
Ombre Eternelle	France	Black Metal	Split-up
Omean	United States	Sludge/Doom Metal	Active
Omega	Greece	Black/Thrash Metal	Active
Omega	Italy	Death Metal	Split-up
Omega	United Kingdom	Heavy Metal/Progressive Rock/NWOBHM	Split-up
Omega	France	Melodic Death/Black Metal	Active
Omega 218	Italy	Black Metal	Changed name
Omega Apeiron	Italy	Black Metal	Unknown
Omega Centauri	International	Atmospheric Black Metal	Active
Omega Crom	Canada	Thrash/Power Metal	Active
Omega Flare	Italy	Progressive Metal	Active
Omega Massif	Germany	Sludge Metal	Active
Omega Point	United States	Progressive Metal	Split-up
Omega Ryde	United States	Traditional Heavy Metal	Active
Omega Soul	Germany	Psychedelic Stoner/Doom Metal	Active
Omega Thesis	United States	Technical Doom Metal	Active
Omega Tribe	United States	Thrash/Groove Metal	Active
Omegacell	United States	Doom Metal	Unknown
Omegadoom	Germany	Death Metal/Metalcore	Active
Omegahead	Brazil	Thrash Metal	Active
Omegalord	United States	Heavy Metal	Active
Omegalpha	Brazil	Black Metal	Active
Omen	Hungary	Power/Thrash/Speed Metal	Active
Omen	Malaysia	Black Metal	Active
Omen	South Africa	Thrash Metal	Changed name
Omen	United States	Power Metal	Active
Omen	Australia	Death/Thrash Metal	Active
Omen Faculty	United States	Industrial/Groove Metal	Active
Omen From Hell	Portugal	Melodic Death Metal	Unknown
Omen of Death	United States	Black Metal/Ambient	Active
Omen Searcher	United Kingdom	NWOBHM	Split-up
Omendark	Spain	Pagan Black Metal	Active
Omenomejodas	Spain	Thrash Metal	Active
Omens of Desolation	United States	Doom/Black Metal	Split-up
Omens of Disaster	Belgium	Thrash Metal	Split-up
Omens Thorns	Hungary	Doom/Black Metal	Active
Omerta	United States	Thrash Metal	Active
Omerta	Belgium	Death Metal/Deathcore/Metalcore	Active
Omerta	Vietnam	Thrash/Death Metal	Active
Omfalos	Brazil	Black Metal/Avant-garde	Active
Omichron	United States	Blackened Death Metal	Split-up
Omicidio	Italy	Death/Thrash Metal	Changed name
Omicron	Italy	Death/Black Metal	Unknown
Omicron	Italy	Death Metal	Split-up
Ominos	United States	Melodic Thrash/Heavy Metal	Active
Ominosity	Canada	Doom/Death Metal	Active
Ominous	Finland	Black Metal	Active
Ominous	Spain	Black Metal	Split-up
Ominous	Sweden	Melodic Death/Thrash Metal	Active
Ominous	United States	Death Metal	Active
Ominous Abyss	Ukraine	Doom Metal	Active
Ominous Black	United States	Sludge/Doom Metal/Post-Hardcore	Active
Ominous Conception	United States	Death Metal/Grindcore	Active
Ominous Crucifix	Mexico	Death Metal	Active
Ominous Deathcult	Sweden	Extreme Metal	Active
Ominous Dusk	Netherlands	Thrash Metal	Split-up
Ominous Force	United States	Symphonic Black Metal	Changed name
Ominous Grief	Turkey	Melodic Black/Gothic Metal	Active
Ominous Grim	United States	Black Metal	Active
Ominous Resurrection	United States	Black Metal	Active
Ominous Silence	Germany	Gothic/Doom Metal	Split-up
Ominous Sky	Greece	Epic/Doom Metal	Active
Ominous Yum Cimil	Mexico	Black Metal	Active
Omision	Mexico	Death Metal	Active
Omission	United Kingdom	Thrash/Groove Metal	Unknown
Omission	Spain	Thrash Metal	Active
Omit	Norway	Doom Metal	Active
Omitah	Brazil	Heavy/Power Metal	Active
Omitir	Portugal	Black Metal	Active
Ommadon	United Kingdom	Doom Metal	Active
Ommatidia	France	Gothic Metal	Active
Omneity	United States	Black/Death Metal	Active
Omni Mortuus	United States	Black/Dark/Gothic Metal	Split-up
Omnia Malis Est	Italy	Black Metal	Active
Omnia Orta Cadunt	Russia	Black Metal	Split-up
Omnicidal System	United States	Crossover/Thrash Metal	Split-up
Omnicide	Switzerland	Death/Thrash Metal	Active
Omnicide	United Kingdom	Power/Thrash Metal	Active
Omnicide	Australia	Death Metal	Unknown
Omnicide	Russia	Black Metal	Split-up
Omnicide	United States	Black Metal	Active
Omnicrom	United States	Thrash Metal	Split-up
Omnihierophantom	Netherlands	Melodic Black/Death Metal	Unknown
Omnihility	United States	Technical/Brutal Death Metal	Active
Omnipotence	Norway	Death/Doom Metal	Unknown
Omnipresent	United States	Progressive Metal	Active
Omniscient	United States	Symphonic Black Metal	Active
Omnispawn	Sweden	Melodic Death/Thrash Metal	Active
Omnitron	Sweden	Thrash Metal	Split-up
Omnium	Australia	Death Metal/Grindcore	Active
Omnium Gatherum	Australia	Death Metal/Grindcore	Changed name
Omnium Gatherum	Finland	Melodic Death Metal	Active
Omnivores	Germany	Melodic Black/Death Metal	Active
Omnivorous	Austria	Death Metal	Split-up
Omnizide	Sweden	Black/Death Metal	Active
Omonimo	Italy	Black/Death Metal	Split-up
Omophagia	Switzerland	Death Metal	Active
Omotai	United States	Progressive Sludge Metal	Active
ON	Spain	Melodic Black/Death Metal	Active
On a Pale Horse	United States	Heavy/Stoner Metal	Split-up
On Broken Wings	United States	Metalcore	Active
On Fucking Air	Spain	Melodic Heavy Metal	Active
On Horns Impaled	Germany	Black Metal	Split-up
On Pain of Death	Ireland	Death/Doom Metal	Active
On Paths of Torment	United States	Melodic Death Metal	Changed name
On the Edge	France	Melodic Death/Thrash/Groove Metal	Split-up
On the Edge of the NetherRealm	Russia	Gothic/Doom/Death Metal	Split-up
On Thorns I Lay	Greece	Death/Doom Metal (early), Gothic Metal (mid), Hard Rock (later)	Active
On Top	United States	Heavy Metal/Hard Rock	Active
On Wings	Bulgaria	Doom Metal	Unknown
On Wings ov Pestilence	Russia	Black Metal	Active
On With Life	Austria	Thrash Metal/Crossover	Active
Onanator	Serbia	Thrash/Speed metal	Active
Onas	Argentina	Thrash/Death Metal	On hold
Onass	Austria	Progressive Metal/Rock	Changed name
Onatem	Italy	Thrash/Groove Metal	Active
Once Beloved	United States	Melodic Death/Thrash/Metalcore	Active
Once Dead	United States	Heavy/Thrash Metal	Active
Once Forgotten	United States	Death/Black Metal	Unknown
Once Godlike	Belgium	Death Metal (early), Metalcore (later)	Active
Once I Tried	United Kingdom	Technical Death Metal/Grindcore	Split-up
Once Nothing	United States	Metalcore	Split-up
Once Pure	United States	Post-Thrash/Groove Metal/Metalcore	Active
Once Shot Trouble	Ukraine	Death Metal/Metalcore	Active
Once Solemn	Germany	Melodic Death Metal	Active
Once There Was	Sweden	Symphonic/Gothic Metal	Active
Once Was Silence	Italy	Gothic/Avant-garde Metal (early), Avant-garde/Death/Noise (later)	Split-up
Onceover	United States	Thrash Metal/Crossover	Split-up
Ond Aand	France	Black/Death/Dark Metal	Split-up
Onde Spherique	Germany	Atmospheric Sludge Metal	Active
Onderah	Romania	Gothic/Symphonic Metal	Split-up
Ondrim	Finland	Black Metal	Split-up
Ondska	Sweden	Black Metal	Split-up
Ondskapt	Sweden	Black Metal	Active
Ondske	Sweden	Black Metal	Changed name
One	United States	Heavy Metal	Split-up
One Against the Grain	United States	Progressive/Thrash Metal	Unknown
One Bad Apple	United States	Thrash Metal/Crossover	Active
One Bullet Left	Netherlands	Groove/Death Metal	Active
One Dead Dream	Australia	Thrash/Metalcore	Split-up
One Dead Three Wounded	United States	Southern Metal/Metalcore	Split-up
One Desire	Spain	Melodic Death Metal	Split-up
One Eight Seven	Belgium	Death Metal	Split-up
One Eye Open	United States	Heavy Metal	Unknown
One Eyed Monster	Spain	Thrash Metal	Unknown
One Hour Hell	Sweden	Thrash/Death Metal	Active
One Inch Giant	Sweden	Stoner/Doom Metal	Active
One Last Sin	United States	Death Metal/Hardcore	Split-up
One Last Victim	Japan	Death Metal/Grindcore	Split-up
One Last Word	Spain	Melodic Death Metal/Metalcore	Active
One Law for the Lion	Colombia	Black/Death Metal	Active
One Louder	United Kingdom	Heavy Metal	Active
One Man Army and the Undead Quartet	Sweden	Death/Thrash Metal	Split-up
One Man Overture	United Kingdom	Heavy Metal	Active
One Man's Fate	Germany	Groove/Thrash Metal	Split-up
One Man's Hell	Chile	Death Metal	Active
One Master	United States	Black Metal	Active
One Million Dead	Brazil	Raw Black Metal	Unknown
One More Day	Germany	Gothic Metal	Split-up
One More Lie	Turkey	Melodic Death Metal/Metalcore	Active
One More Victim	Russia	Death Metal/Deathcore	Active
One of Sixx	United States	Power Metal	Active
One of Them	Brazil	Thrash Metal	Active
One of These Days	Greece	Death Metal/Grindcore	Active
One on One	Netherlands	Thrash/Groove Metal	Active
One Orphan More	Finland	Melodic Metal	Active
One Out of Hell	Slovenia	Thrash/Groove Metal	Unknown
One Past Zero	Germany	Stoner Metal	Split-up
One Per Coffin	United States	Death Metal/Grindcore	Active
One Shot for All	Russia	Technical Progressive Death Metal/Deathcore	Active
One Sign of Metal	Germany	Progressive Metal	Active
One Slack Mind	United States	Groove/Stoner Metal	Active
One Solution Only	United States	Melodic Death Metal	Active
One Soul	Germany	Thrash Metal/Crossover	Active
One Step Beyond	Australia	Experimental Death Metal	Active
One Step Beyond	United States	Melodic Heavy Metal	Split-up
One Tail, One Head	Norway	Black Metal	Active
One We Created	United States	Technical Death Metal/Deathcore	Active
One With Nothing	United States	Death Metal	Unknown
One Without	Sweden	Gothic Metal / Metalcore	Active
Onedice	United Kingdom	Hardcore/Death Metal	Split-up
Oneiric Realm	United States	Progressive Black Metal	Split-up
Oneiroi	United States	Black Metal	Split-up
Oneiros	Germany	Melodic Dark Metal	Split-up
Oneiros	Italy	Power Metal	Split-up
Oneroid Blood Pressure	Russia	Brutal Death Metal/Grindcore	Active
Onfall	Italy	Hardcore (early), Melodic Death Metal/Metalcore (later)	Active
Onheil	Netherlands	Black Metal	Active
Oni	Australia	Brutal Death Metal	Split-up
Onicectomy	Italy	Brutal Death Metal	Active
Oniria	Argentina	Gothic Metal	Active
Onirica	Ecuador	Melodic Death Metal	Active
Onirica	Italy	Black Metal	Active
Onirik	Portugal	Black Metal	Active
Onirik	Italy	Brutal Death Metal	Active
Oniromancia	France	Black Metal	Split-up
Oniromancy	France	Speed/Power/Heavy Metal	Active
Oniromantic	Italy	Gothic/Power Metal	Active
Onirophagus	Spain	Doom/Death Metal	Active
Onita	United States	Sludge/Southern Metal	Active
Onkel Tom Angelripper	Germany	Thrash Metal	Active
Onkunde	Netherlands	Black Metal/Harsh Noise	Active
Only Blood	Spain	Death Metal	Split-up
Only Darkness	France	Black Metal	Split-up
Only Death Decides	Germany	Melodic Death Metal/Metalcore	Active
Only Death Remains	Germany	Death Metal/Metalcore	Split-up
Only Fate Remains	Netherlands	Gothic Metal/Rock	Active
Only Hell Remains	United States	Thrash Metal, Hardcore	Changed name
Only Human	United States	Progressive Thrash Metal/Grindcore	On hold
Only Living Witness	United States	Thrash Metal with hardcore influences	Split-up
Ono Turmna	Switzerland	Black/Death Metal	Split-up
Onore Distruzione	Italy	Thrash Metal	Unknown
Onrust	Netherlands	Black Metal	Changed name
Onset of Serious Problems	Indonesia	Thrashcore/Grindcore	Active
Onsetcold	United Kingdom	Death Metal	Active
Onslaught	United Kingdom	Hardcore Punk (early), Thrash Metal (later)	Active
Onslaught	United States	Power Metal	Unknown
Onslaught	India	Power/Thrash/Groove Metal	Active
Onslaughter	Philippines	Brutal Death/Black Metal	Changed name
Onslaughterator	United States	Black/Death Metal	Unknown
Ontogeny	United States	Technical/Progressive Death Metal	Active
Ontos On	Canada	Black Metal	Unknown
Onus	United States	Melodic Death Metal	Active
Onward	United States	Traditional/Power Metal	Split-up
Onward to Olympas	United States	Melodic Death Metal/Metalcore	Active
Onward We March	United States	Groove Metal/Metalcore	Active
Onyricon	Italy	Progressive Metal with Rock influences	Active
Onyx	Sweden	Heavy Metal	Split-up
Onyx Eyes	Germany	Gothic/Progressive Metal	Active
Oof Expain	Sweden	Thrash Metal	Split-up
oOo	France	Industrial Black Metal	Changed name
Oorlogsgoden	Brazil	Brutal Death Metal	Active
Ooze	Italy	Sludge Metal	Active
Opacity	Germany	Dark/Black Metal	Active
Opacity	Sweden	Black Metal	Split-up
Opacity of Evil	Netherlands	Death/Thrash Metal	Split-up
Opacus	United Kingdom	Black Metal	Active
Opalessence	Germany	Gothic Metal	Active
Opaq	United States	Progressive/Experimental/Gothic Metal	Active
Opaque	Netherlands	Doom/Dark Metal	Active
Opaque	United States	Groove/Metalcore	Split-up
Opaque Mirror	Puerto Rico	Melodic Death Metal	Split-up
Opaque Notation	United States	Death Metal/Grind	Split-up
Open	Netherlands	Death Metal/Grindcore	Unknown
Open Casket	Portugal	Death Metal	Split-up
Open Casket	Ireland	Death Metal	Active
Open Denile	United States	Progressive/Melodic Death Metal	Active
Open Festering Wounds	Australia	Death/Thrash Metal	Split-up
Open Fire	Poland	Heavy Metal	Unknown
Open Fire	Romania	Thrash Metal (early), Death/Thrash Metal (later)	Active
Open Grave	United States	Death/Doom Metal	Active
Open Grave	United States	Black Metal	Active
Open Heart Supper	United States	Black/Thrash Metal	Active
Open Hell	Poland	Black Metal	On hold
Open Mind	Argentina	Heavy Metal	Active
Open Mind	United States	Power Metal	Split-up
Open Rebuke	United States	Progressive Metal	Active
Open Scars	Brazil	Brutal Death Metal	Active
Opened Paradise	Greece	Atmospheric Gothic Rock/Metal	Active
Opening Scenery	Italy	Progressive Power Metal	Active
Opensight	Colombia	Progressive Heavy Metal	Active
Openwide	Sweden	Dark/Doom Metal	Active
Opera	Brazil	Melodic Heavy Metal	Split-up
Opera	Italy	Progressive Metal	Split-up
Opera	Sweden	Black Metal	Active
Opera	Germany	Progressive Metal	Changed name
Opera Diabolicus	Sweden	Epic Heavy/Gothic/Doom/Progressive Metal	Active
Opera Funerea	Italy	Black/Doom Metal	Active
Opera IX	Italy	Gothic Metal (early), Black Metal (later)	Active
Opera Magna	Spain	Power Metal	Active
Opera Manent	Spain	Progressive Heavy/Thrash Metal	Unknown
Operadyse	France	Symphonic Power Metal	Active
Operatika	United States	Opera/Symphonic Power Metal	Active
Operation Corpse	Malaysia	Death/Thrash Metal	Changed name
Operation Counterstrike	Germany	Death Metal	Changed name
Operation Downfall	United States	Melodic Death Metal	Split-up
Operation Mindfuck	Germany	Technical Death Metal	Active
Operation Winter Mist	Canada	Black Metal	On hold
Operator Generator	United States	Stoner Metal/Rock, Doom Metal	Split-up
Opereth Sin	Italy	Symphonic Gothic Metal	Split-up
Opertum	Greece	Death Metal	Split-up
Opeth	Sweden	Extreme Progressive Metal (early), Progressive Rock (later)	Active
Opfer Rassenhass	Canada	NS Black Metal	Active
Opferblut	Germany	Black Metal	Active
Opferdolch	Germany	Black Metal	Active
Opfertod	Czech Republic	Black Metal	Active
Ophelia	United Kingdom	Melodic Death/Thrash/Groove Metal	Active
Ophelia	Pakistan	Groove Metal	Split-up
Ophelia's Nightmare	Germany	Gothic Metal	Active
Ophian	United States	Black Metal	Active
Ophidian	Slovenia	Progressive Thrash Metal	Split-up
Ophidian	Luxembourg	Heavy/Thrash Metal	Active
Ophidian	Italy	Melodic Death Metal	Split-up
Ophidian Forest	International	Pagan/Black Metal	Active
Ophidian I	Iceland	Technical Death Metal	Active
Ophidian Ritual	United Kingdom	Black Metal/Noise/Ambient	Active
Ophidyan	Germany	Gothic Metal	Split-up
Ophiolatry	Brazil	Brutal Death Metal	Split-up
Ophis	Germany	Death/Doom Metal	Active
Ophiuchus	United States	Black/Death/Thrash Metal	Active
Ophiura	Italy	Progressive Metal	Active
Ophthalamia	Sweden	Black Metal	Split-up
Ophydian	Italy	Thrash / Heavy Metal	Changed name
Ophyra	Italy	Melodic Death Metal	Active
Opinicus	United Kingdom	Melodic Death Metal	Active
Opion	Germany	Doom Death Metal	Split-up
Opitz	Czech Republic	Grindcore / Brutal Death Metal	Active
Opium	Portugal	Death Metal	Split-up
Opium	Indonesia	Brutal Death Metal	Active
Opium Warlords	Finland	Blackened Drone/Doom Metal, Rock	Active
Opositor	Hungary	Black Metal	Active
Opozit	France	Metalcore	Split-up
Opponent	France	Technical Death Metal	Split-up
Opportunity	Thailand	Thrashcore	Active
Opposed	Germany	Progressive Thrash Metal	Active
Opposed to Violence	Germany	Progressive Doom/Death Metal	Changed name
Opposing Motion	United Kingdom	Progressive Metal	Active
Opposite Earth	United States	Progressive Power Metal	Split-up
Opposite Sides	Italy	Melodic Death Metal	Active
Opposition	Russia	Technical Death Metal	Changed name
Opposition Party	Singapore	Hardcore/Punk (early), Thrash/Groove Metal (later)	Active
Oppression	France	Thrash/Death Metal	Split-up
Oppression	Sweden	Thrash Metal	Split-up
Oppression	Finland	Death/Thrash Metal with Doom influences	Split-up
Oppressive Light	International	Depressive Black Metal	Active
Oppressor	Germany	Death Metal	Active
Oppressor	Poland	Death Metal	Changed name
Oppressor	United States	Technical Death Metal	Split-up
Opprobrium	United States	Death/Thrash Metal	Active
Opresor	Argentina	Thrash Metal	Active
Opresor	Peru	Thrash Metal	Active
OPROM	Spain	Brutal Death Metal	Split-up
Optic	United States	Progressive Metal	Active
Opticollide	United States	Melodic Gothic/Heavy Metal	Split-up
Optimum Fury	United States	Speed/Thrash Metal	Split-up
Optimus Prime	United States	Power Metal	Split-up
Optimystical	Sweden	Melodic Heavy Metal/Hard Rock	Active
Optoletum	Norway	Black Metal	Unknown
Opus	France	Symphonic Heavy Metal	Split-up
Opus Altera	Hungary	Progressive Metal	Active
Opus Atlantica	Sweden	Progressive/Power Metal	Unknown
Opus Cruor	Brazil	Black Metal	Active
Opus Dead	Spain	Crossover	Active
Opus Death	Peru	Black/Doom Metal	Split-up
Opus Dei	United States	Progressive Black Metal	Unknown
Opus Diaboli	Uruguay	Black Metal	Active
Opus Doria	France	Symphonic Power/Gothic Metal	Active
Opus Draconis	Portugal	Black Metal	Active
Opus Forgotten	Norway	Black Metal	Active
Opus Inferii	Brazil	Black Metal	Active
Opus Magorum	Greece	Black Metal	Active
Opus Majestic	United States	Symphonic Folk 'Black' Metal (early), Industrial/'Black' Metal (later)	Active
Opus Maledicta	Italy	Symphonic Black Metal	Active
Opus Malefici	Italy	Death/Black Metal	Split-up
Opus Mortem	Sweden	Black Metal	Unknown
Opus Mortifer	Italy	Black Metal	Active
Opus Nex	United Kingdom	Death/Thrash Metal	Unknown
Opus Nocturnales	Belgium	Black Metal	Active
Opus Nocturne	Mexico	Black Metal	Changed name
Opus Nocturne	Poland	Black Metal	Split-up
Opus Obscurium	Denmark	Symphonic Black Metal	Split-up
Opus Profanus	Brazil	Black Metal	Active
Opus Sacrum	Poland	Death/Thrash Metal	Split-up
Opus Sinistra	Argentina	Black Metal	Active
Opus Symphonia	Indonesia	Melodic Black/Gothic Metal	Active
Opus VII	Chile	Melodic Doom/Death Metal	Active
Opus666	Brazil	Black/Heavy Metal	Unknown
Opvs Leviathan	Colombia	Epic Black Metal	Active
Opvs Nostri	Brazil	Black Metal	Active
Ora Nombro	Italy	Progressive Metal	Active
Ora Pro Nobis	Venezuela	Gothic Metal	Unknown
Ora Pro Nobis	Russia	Progressive Doom Metal	Split-up
Oracle	Gibraltar	Melodic Heavy Metal	Split-up
Oracle	Malaysia	Melodic Death Metal	Active
Oracle	United States	Heavy Metal	Split-up
Oracle	Indonesia	Industrial Metal/Rock (early) Thrash/Gothic Metal (later)	Active
Oracle of Fire	United States	Symphonic Death/Black Metal	Active
Oracle of the Void	Australia	Black/Death Metal	Split-up
Oracle Sun	Italy	Power/Progressive Metal	Unknown
Oracles Oath	United Kingdom	Symphonic/Progressive Metal	Active
Oracular Discander	Israel	Death/Doom Metal	Split-up
Oraculo	Brazil	Doom Metal	Split-up
Oraculo	Brazil	Power Metal	Active
Oraculo	Brazil	Heavy Metal	Active
Oraculum	Italy	Black Metal	Unknown
Orage	Canada	Heavy Metal	Split-up
Oraison Funebre	France	Black Metal	Active
Orakle	France	Atmospheric Black Metal	Active
Oral	United Kingdom	Heavy Metal	Split-up
Oral	Sweden	Death / Crust	Split-up
Oral Fistfuck	Switzerland	Brutal Death Metal	Active
Orange Diesel	United States	Stoner Metal/Rock	Active
Orange Goblin	United Kingdom	Doom Metal, Stoner Metal	Active
Orange Hill	Belgium	Death/Thrash Metal	Active
Oranssi Pazuzu	Finland	Psychedelic Black Metal	Active
Orant	Czech Republic	Black Metal	Active
Orate	Argentina	Death/Black Metal	Active
Orate	Chile	Stoner/Sludge/Doom Metal/Grunge	Unknown
Orategod	Chile	Brutal Death Metal	Active
Orator	Bangladesh	Death/Thrash Metal	Active
Oratoria	France	Death/Thrash Metal	Split-up
Oratorio	Ukraine	Gothic/Doom Metal	Split-up
Oratorio	Finland	Power Metal	Active
Oratory	Portugal	Symphonic Power Metal	Active
Orb of Confusion	United States	Thrash/Stoner Metal	Split-up
Orb of Torture	Belgium	Death Metal	Unknown
Orca	Croatia	Heavy/Thrash Metal	Active
Orchard	Poland	Doom Metal with Death Metal Influences	Active
Orchards of Odenwrath	Sweden	Death Metal	Split-up
Orchestral Pit's Cannibals	Russia	Grindcore	Split-up
Orchid	United States	Doom Metal	Active
Orchid	Italy	Black Metal	Split-up
Orchid Ablaze	Australia	Metalcore / Melodic Death	Split-up
Orchid Dawn	United Kingdom	Gothic Metal	Unknown
Orchid Visions	Costa Rica	Melodic Heavy Metal	Active
Orchid Void	Japan	Progressive Death / Thrash Metal	Active
Orchidea	Czech Republic	Heavy Metal	Active
Orchidectomy	Canada	Brutal Death Metal	Split-up
Orchidia	Spain	Melodic Death/Groove Metal/Metalcore	Active
Orchrist	Belgium	Melodic Death Metal	Split-up
Orchriste	Sweden	Death/Thrash Metal	Split-up
Orcish Blood	Russia	Melodic Black Metal	Split-up
Orcivus	Sweden	Black Metal	On hold
Orckout	Brazil	Thrash Metal	Unknown
Orconirom	Colombia	Heavy Metal	Active
Orcrist	Italy	Black Metal	Active
Orcrypt	United Kingdom	Black Metal	Active
Orcses	Austria	Death Metal	Active
Orctod	Germany	Black Metal	Active
Orcus	Algeria	Black Metal	Active
Orcus	United States	Black/Death Metal	Active
Orcus	United States	Power Metal (early), Death Metal (later)	Active
Orcus	Poland	Black Metal	Split-up
Orcus	Mexico	Melodic Death Metal	Unknown
Orcus	Greece	Heavy/Black Metal (early) Heavy Metal (later)	Split-up
Orcus Ater	Chile	Melodic Black Metal	Active
Orcus Castellum	Russia	Black Metal	Split-up
Orcus O Dis	Mexico	Melodic Death Metal	Active
Orcus Tyrannus	Spain	NS Black Metal	On hold
Orcustus	Norway	Black Metal	Active
Ordained	United States	Thrash Metal	On hold
Ordained Fate	United States	Power/Thrash Metal	Split-up
Ordained Genocide	United States	Death Metal	Split-up
Ordalia	Bolivia	Heavy Metal	Active
Ordalia	Italy	Heavy Metal	Split-up
Ordalium	Russia	Melodic Death/Black Metal	Active
Ordeal	Belgium	Death Metal	Split-up
Ordeal	Germany	Melodic Death/Doom Metal	Split-up
Ordeal of Soul	Finland	Melodic Death Metal	Split-up
Ordem Maligna	Brazil	Death Metal	On hold
Orden	Russia	Heavy/Thrash Metal	Split-up
Orden Ogan	Germany	Folk Metal (early), Power Metal (later)	Active
Order 66	United States	Thrash/Death Metal/Hardcore	Active
Order from Chaos	United States	Black/Death Metal	On hold
Order of Bileth	United States	Black Metal	Active
Order of Chaos	Australia	Melodic Death Metal/Metalcore	Split-up
Order of Chaos	Puerto Rico	Thrash with Death Metal influences	Split-up
Order of Ennead	United States	Black/Death Metal	Active
Order of Nine	United States	Power Metal	Active
Order of Orias	Australia	Black/Death Metal	Active
Order of Sekhmet	United States	Black Metal	Split-up
Order of Splendour	Bulgaria	Black Metal	Split-up
Order of Tepes	United Kingdom	Black Metal	Active
Order of Terror	United Kingdom	Black Metal	Active
Order of the Black Guard	United Kingdom	Black Metal	Active
Order of the Black Sun	United Kingdom	Thrash Metal	Active
Order of the Buzzard	Australia	Death / Thrash with Groove influences	Active
Order of the Ebon Hand	Greece	Black Metal	Active
Order of the Gash	United States	Black/Thrash Metal	Active
Order of the Jackal	United States	Groove Metal/Alternative Rock	Active
Order of the Vulture	United States	Death Metal/Crust/Hardcore	Active
Order of the White Hand	Finland	Pagan/Black Metal	Active
Order of Torment	Australia	Black/Death Metal	Active
Order of Tyr	United States	Symphonic Power Metal with Electronic influences	Active
Order to Ruin	Germany	Melodic Death Metal	Active
Ordered Chaos	United States	Heavy/Thrash Metal	Split-up
Ordinance	Finland	Black Metal	Active
Ordinance	United States	Progressive Death Metal	Active
Ordine Nero	United States	NS Black Metal	Active
Ordinul Negru	Romania	Black Metal	Active
Ordnance	China	Thrash/Groove Metal	Active
Ordnance	Australia	Death Metal	Active
Ordo Blasphemus	France	Black Metal	Active
Ordo Caper	Costa Rica	Death Metal	Active
Ordo Draconis	Netherlands	Black Metal/Post-Black Metal	Active
Ordo Infandorum Rituum Occultus	Switzerland	Black Metal, Ambient	Active
Ordo Natum Bamay Crom	Brazil	Viking/Black Metal	Active
Ordo Obsidium	United States	Funeral Doom/Black Metal	Active
Ordo Satanii	Brazil	Black Metal	Active
Ordo Templi Aeternae Lucis	France	Black Metal	Changed name
Ordo Templi Hiereus	Brazil	Black Metal	Split-up
Ordo Templi Orientis	Belarus	Atmospheric/Depressive Black Metal	Split-up
Ordo Tyrannis	United States	Industrial Black Metal	Active
Ordog	Colombia	Black Metal	Active
Ordog	United Kingdom	Black Metal	Split-up
Ordog	France	Black Metal	Active
Ordog	Russia	Black Metal	Split-up
Ordog	Finland	Doom/Death Metal	Active
Ordogiel	Chile	Brutal Death Metal	Active
Ordomalleus	United States	Melodic Heavy/Black Metal	Split-up
Ordoth	Indonesia	Death Metal	Active
Ordoxe	Canada	Black Metal	Active
Ordrenekt	Norway	Thrash Metal/Crossover	Active
Oremus	Poland	Black Metal	Active
Oremuz	Philippines	Atmospheric / Dark Gothic Metal	Active
Orenda	France	Progressive Metal	Active
Orenda	Bulgaria	Black Metal	Active
Orenda	Finland	Stoner Rock/Metal	Active
Orestea	United Kingdom	Melodic Gothic Metal	Active
Orestes	Indonesia	Death Metal	Active
Orfeo	Peru	Power Metal	Active
Orfeu Rebelde	Portugal	Industrial/Gothic Metal, Ambient	Active
Orfeus	Hungary	Heavy Metal	Active
Orfos	Spain	Heavy Metal	Active
Orfvs	Finland	Melodic Black Metal	Active
Organ	United States	Thrash Metal/Grindcore	Changed name
Organ Bizarre	Japan	Death Metal/Grindcore	Unknown
Organ Donor	United States	Heavy/Groove Metal	Unknown
Organ Grinder	United States	Avant-garde Black Metal	Active
Organ Grinder	United Kingdom	Brutal Death Metal/Goregrind	Active
Organ Grinder	France	Death Metal/Grindcore	Split-up
Organ Harvest	United States	Brutal Death Metal	Split-up
Organ Harvest	France	Brutal Death Grind	Split-up
Organ Trails	Switzerland	Black Metal	Changed name
Organ:	Norway	Experimental/Post-Black Metal	Active
Organa	Italy	Viking Metal with Folk Influences	Changed name
Organectomy	New Zealand	Brutal Death Metal	Active
Organic Infest	Puerto Rico	Death Metal	Changed name
Organic Transcendence	Sweden	Death Metal	Active
Organism	United States	Progressive Death Metal	Unknown
Organismos	Colombia	Death Metal/Grindcore	Active
Organized Chaos	Serbia	Progressive Metal	Active
Organized Kaos	Canada	Thrash Metal	Split-up
Orgasm Crazy	Brazil	Death Metal	Split-up
Orgasmic Tears	France	Melodic Death Metal	Active
Orgasmo de Porco	Brazil	Crossover/Thrash Metal	Active
Orghia	Italy	Thrash/Death Metal	Active
Orgiastic Martyrs	Germany	Thrash Metal	Split-up
Orgiastic Pleasures	Italy	Black/Death Metal	Active
Orgon	Spain	Thrash Metal/Crossover	Split-up
Orgone	Mexico	Thrash Metal	Split-up
Orgone	United States	Technical Death Metal	Active
Orgullo Blanco	Chile	NS Black Metal	Split-up
Orgus	Peru	Heavy Metal	Active
Orgy for Satan	United States	Death Metal/Grindcore	Unknown
Orgy of Flies	Brazil	Thrash/Death Metal	Active
Orgy of Pigs	Australia	Death Metal/Grindcore	Split-up
ORH+	Portugal	Death/Thrash Metal	Split-up
Orialix	France	Heavy Metal	Split-up
Orias	United States	Metalcore	Unknown
Oriax	United States	Death Metal	Split-up
Orient	Czech Republic	Hard Rock (early), Heavy Metal (later)	Active
Orient Ende	Thailand	Progressive/Gothic Metal	Active
Orifice	Italy	Grindcore	Split-up
Origam	Turkey	Power/Thrash Metal	Active
Origin	United States	Technical Brutal Death Metal	Active
Origin	United Kingdom	Thrash/Heavy Metal	Active
Origin Blood	Sweden	Death/Thrash Metal	Active
Origin of Anger	Japan	Brutal Death/Thrash Metal	Active
Origin of Darkness	United States	Death/Funeral Doom/Metal	Active
Origin of Plague	Korea, South	Black Metal	Active
Origin of Silence	United States	Progressive Metal	Changed name
Origin of Storm	Turkey	Thrash/Groove Metal	Active
Origin of Zed	Germany	Death/Thrash Metal	Active
Origin'Hell	France	Death/Thrash Metal	Active
Original Chaotic Addiction	France	Death/Thrash Metal	Active
Original Gravity	Italy	Thrash Metal/Crossover	Split-up
Original Sin	United States	Speed/Power Metal	Split-up
Original Sin	United Kingdom	Heavy Metal	Split-up
Original Sin	United Kingdom	Death/Thrash Metal	Active
Original Sin	United States	Heavy Metal	Split-up
Original Sin	United Kingdom	NWOBHM	Split-up
Originy	Finland	Gothic Power Metal	Unknown
Orion	Poland	Thrash Metal	Split-up
Orion	Italy	Heavy/Power/Thrash Metal	Split-up
Orion	Netherlands	Heavy Metal	Split-up
Orion	United Kingdom	Black Metal	Split-up
Orion	United Kingdom	Thrash/Groove Metal	Active
Orion	Russia	Melodic Black Metal	Active
Orion	Macedonia (FYROM)	Death/Thrash Metal	Split-up
Orion	Argentina	Power Metal	Active
Orion	Syria	Melodic Death/Thrash Metal/Metalcore	Active
Orion	India	Progressive Death Metal	Active
Orion	Venezuela	Power Metal	Split-up
Orion	Chile	Thrash/Death Metal	Active
Orion	United Kingdom	NWOBHM, Heavy Metal	Split-up
Orion	Spain	Heavy Metal	Active
Orion	Belarus	Heavy/Thrash Metal	Changed name
Orion	Sweden	Melodic Death Metal	Active
Orion	Pakistan	Thrash Metal	Split-up
Orion	Sweden	Power/Heavy Metal	On hold
Orion	Colombia	Melodic Heavy Metal	Split-up
Orion	Colombia	Heavy Metal	Split-up
Orion Belt	Russia	Black Metal/Noise/Ambient	Active
Orion Child	Spain	Power Metal	Active
Orion Nightfall	Finland	Black/Death Metal	Active
Orion Prophecy	Poland	Melodic Death Metal	Active
Orion Riders	Italy	Symphonic / Melodic Power Metal	Active
Orion's Descent	United States	Melodic Thrash Metal	Unknown
Orion's Night	Belgium	Symphonic Death Metal	Active
Orion's Reign	Greece	Heavy/Power Metal	Active
Orion's Sword	Sweden	Heavy Metal	Split-up
Orion's Void	Greece	Doom Metal	Active
Orisha Shakpana	Jamaica	Black Metal	Active
Orivanna	Switzerland	Black/Doom Metal with Folk elements	Active
Oriz	Sweden	Melodic Heavy Metal	Active
Orizen	Switzerland	Black/Pagan Metal	Active
Orjarat	Hungary	Death Metal	Split-up
Orjatalvi	Finland	Black Metal	Active
Ork	Spain	Black Metal	Split-up
Ork	Bulgaria	Black Metal	Active
Ork Bastards	Russia	Thrash Metal	Active
Orkkid	Serbia	Melodic Folk Metal	Unknown
Orkrist	Slovakia	Melodic Black/Doom/Heavy Metal	Split-up
Orkum Morari	Germany	Gothic Metal/Rock	Split-up
Orkus	Germany	Black Metal	Split-up
Orkyd Orchestra	Germany	Gothic/Power Metal	Active
Orlac	Spain	Death Metal	Split-up
Orlag	France	Black/Death Metal	Active
Orloff	United States	Death Metal	Active
Orlog	Germany	Black Metal	Active
Orlok	Sweden	Heavy/Thrash Metal	Split-up
Orm	United States	Sludge/Drone/Doom Metal	Active
Ormer	Norway	Black Metal	Active
Ormgard	Sweden	Black Metal/Ambient	Active
Ormus	Bosnia and Herzegovina	Melodic Thrash/Death Metal	Active
Ormuz	Ecuador	Black Metal	Split-up
Orn	Canada	Doom/Sludge Metal	Split-up
Orna Annon	United States	Viking Metal	Split-up
Ornament of Disgrace	United States	Death Metal	Split-up
Ornamental Virus	Belgium	Experimental/Progressive Metal	Split-up
Ornaments of Agony	Mongolia	Funeral Doom/Death Metal	Active
Ornaments of Sin	France	Black Metal	Active
Orne	Finland	Progressive Rock	Active
Ornias	Sweden	Black Metal	Active
Ornimental	United States	Thrash/Groove Metal	Active
Oro	Sweden	Death Metal	On hold
Oro	Spain	Heavy Metal	Split-up
Oro Negro	Spain	Heavy Metal	Split-up
Oro Verde	Mexico	Heavy Metal	Split-up
Orob	France	Progressive Black Metal/Post Metal	Active
Orochi	France	Death Metal	Active
Orodreth	Italy	Death Metal (early), Technical Death Metal (later)	Active
Orodruin	United States	Black Metal	Split-up
Orodruin	United States	Doom Metal	Active
Orodruin	Netherlands	Black/Doom Metal	Split-up
Orodruin	Norway	Black Metal	Unknown
Oroku Saki	Sweden	Power/Heavy Metal	Split-up
Orom	Hungary	Dark Ambient/Gothic/Doom Metal	Active
Oros	Slovakia	Grindcore	Active
Orosius	United States	Black Metal	Split-up
Oroz	Serbia	Heavy Metal	Active
Orpatheedox	Ireland	Melodic Death Metal	Split-up
Orphalis	Germany	Technical Brutal Death Metal	Active
Orphan	Kazakhstan	Death Metal	Split-up
Orphan	United States	Sludge/Groove Metal	Split-up
Orphan Allies	United States	Power Metal	Split-up
Orphan Gypsy	Sweden	Power Metal	Unknown
Orphan Hate	Germany	Melodic Thrash/Death Metal	Active
Orphan Project	United States	Progressive Metal/Rock	Active
Orphanage	Netherlands	Death/Gothic Metal	Split-up
Orphaned Land	Israel	Doom / Death / Middle Eastern Folk Metal (early), Middle Eastern Folk Metal (later)	Active
Orphaned to Hatred	United States	Thrash/Groove Metal	Active
Orphans in Coma	Canada	Death Metal/Metalcore	Split-up
Orphans of Doom	Czech Republic	Heavy Metal	Active
Orpheo	Netherlands	Progressive Metal/Rock	Split-up
Orpheria	Finland	Progressive/Death Metal	Active
Orpheum	United Kingdom	Melodic/Progressive Gothic Metal	Active
Orpheus	Ireland	Progressive Metal	Split-up
Orpheus	Colombia	Dark Metal	Split-up
Orpheus	Norway	Heavy Metal	Active
Orpheus	Australia	Melodic Death Metal	Active
Orpheus	Ecuador	Progressive Metal	Split-up
Orpheus	United Kingdom	Atmospheric Progressive Rock/Metal	Split-up
Orpheus in Mourning	France	Symphonic Black Metal	Split-up
Orphonic Orchestra	United States	Symphonic Gothic/Power Metal (early), Classical/Orchestral Rock/Metal (later)	Split-up
Orquidea Negra	Brazil	Heavy Metal	Active
Orrenda Acciaieria	Italy	Stoner/Progressive Metal	Active
Orrery	Australia	Black Metal	Split-up
Orset	Argentina	Thrash Metal	Active
Orsini	Spain	Thrash Metal/Crossover	Active
Ortank	Poland	Death Metal/Goregrind	Split-up
Ortega	Netherlands	Doom/Sludge Metal	Active
Orteo	Russia	Melodic Power Metal	Active
Orth	Germany	Death Metal	Active
Orthanc	France	Black Metal	Active
Orthanc	Singapore	Pagan Black Metal	Split-up
Orthanc	Argentina	Heavy/Power Metal	Split-up
Orthanc	Russia	Melodic Black/Death Metal	Split-up
Orthanc	Belgium	Heavy Metal	Split-up
Orthaugr	Canada	Black Metal	Split-up
Orthodox	Czech Republic	Thrash / Death Metal	Unknown
Orthodox	Italy	Death/Thrash Metal	Active
Orthodox	Ukraine	Doom Metal	Split-up
Orthodox	Russia	Melodic Death Metal	Active
Orthodox	Ukraine	Death Metal	Active
Orthodox	Spain	Doom Metal	Active
Orthodox Divinity	United Kingdom	Black Metal	Split-up
Orthodox Fuzz	United States	Southern/Stoner Metal/Rock	Active
Orthon	China	Symphonic Black Metal	Active
Orthros	Finland	Melodic Death Metal	Split-up
Orthrus	United States	Black/Thrash Metal	Active
Ortzia	France	Heavy/Thrash Metal	Split-up
Orum	Philippines	Black/Death Metal	Active
ORVKKL	United States	Black Metal	Active
Orwell	United States	Melodic Death Metal/Metalcore	Active
Orylyus	United Kingdom	Progressive Melodic Death Metal	Active
Orzymoth	Germany	Black Metal	Split-up
Osairis	Singapore	Heavy Metal	Active
Osamenta	Argentina	Thrash Metal	Active
Osamenta	Puerto Rico	Death Metal	Split-up
Osamente	Argentina	Death Metal, Grindcore	Split-up
Oscularum Infame	Germany	Black Metal	Split-up
Osculum	Mexico	Black Metal	Active
Osculum Infame	Brazil	Black/Death Metal	Active
Osculum Infame	Greece	Black Metal	Split-up
Osculum Infame	France	Black Metal	Active
Osculum Obscenum	Brazil	Black Metal/Grindcore	Split-up
Oscura	Germany	Death/Doom Metal	Split-up
Oscuriam	Mexico	Symphonic/Gothic Metal	Active
Oscuridad	Colombia	Black Metal	Active
Oscuro	United Kingdom	Death Metal	Split-up
Oscuro Diciembre	Mexico	Melodic Death Metal/Metalcore	Active
Oscvrita	Turkey	Black Metal	Active
Oscypherion	Poland	Black Metal	Active
Osgiliath	France	Medieval Black Metal	Split-up
Osh	Germany	Thrash/Death Metal with Grindcore, Progressive and Rock elements	Split-up
Oshiego	Singapore	Death/Thrash Metal	Active
Oshii	France	Metalcore	Split-up
OSI	United States	Progressive Metal/Rock	Active
Osian	Italy	Heavy/Thrash Metal (early), Dark/Gothic/Mallcore (later)	Active
Osirion	France	Black Metal	Active
Osiris	Austria	Dark/Gothic/Doom Metal	Split-up
Osiris	Italy	Black/Folk Metal	Split-up
Osiris	Netherlands	Progressive Power/Thrash Metal	Changed name
Osiris	United Kingdom	Power Metal	Split-up
Osiris	United States	Groove/Thrash Metal	Split-up
Osiris	Germany	Speed Metal	Split-up
Osiris	Canada	Heavy Metal	Split-up
Osiris	Norway	Thrash/Death Metal	Split-up
Osiris	Spain	Heavy Metal	Split-up
Osiris	Brazil	Heavy Metal	Unknown
Osiris Rising	United States	Atmospheric Heavy Metal	Split-up
Osiris Troopz	Indonesia	Death Metal	Active
Oskal	Russia	NS Black Metal	Active
Oskord	Ukraine	Folk Metal	Active
Oskorei	Germany	Black Metal	Split-up
Oskorei	United States	Thrash/Death/Black Metal	Active
Oskoreien	United States	Viking Metal (early), Black Metal (later)	Active
Oskryf	Finland	Drone/Doom Metal	Active
Osmi Putnik	Croatia	Heavy Metal	Active
Osmidrosis Torture	Japan	Death Metal	Unknown
Osmium	United Kingdom	Heavy/Stoner Metal	Active
Osmium	New Zealand	Southern/Groove Metal	Active
Osmium	United States	Thrash Metal	Active
Osmium Grid	Australia	Death Metal/Death 'n' Roll	Active
Osmium Guillotine	United Kingdom	Heavy Metal	Active
Osmosis	Spain	Death/Black Metal/Grindcore	Active
Osobrom	Chile	Death/Black Metal	Active
Ossadogva	Ukraine	Depressive Black Metal	Active
Ossarios	Brazil	Death/Thrash Metal	Active
Ossarium	Italy	Black Metal	Split-up
Ossarium	Germany	Doom/Death Metal	Active
Ossarivm	Portugal	Death Metal	Active
Ossastorium	Lithuania	Melodic Death Metal	Active
Ossea Cyphus	United States	Raw Black Metal	Active
Ossein	United States	Atmospheric Black Metal/Acoustic/Ambient	Active
Ossian	Turkey	Black/Death Metal	Split-up
Ossian	Italy	Heavy Metal	Split-up
Ossian	Hungary	Traditional/Power Metal	Active
Ossification	Italy	Death Metal	Split-up
Ossification	United States	Death Metal	Active
OSSM	United States	Sludge/Doom Metal	Unknown
Ossuaire	France	Death Metal	Active
Ossuarist	United States	Death Metal/Grindcore	Split-up
Ossuary	United States	Death Metal	Split-up
Ossuary	Belarus	Brutal Death Metal	Active
Ossuary	Uruguay	Death Metal	Split-up
Ossuary	Lithuania	Death Metal	Split-up
Ossuary	Chile	Death Metal	Split-up
Ossuary	Czech Republic	Death Metal	Split-up
Ossuary	Singapore	Thrash Metal	Split-up
Ossuary	United States	Death Metal/Grindcore	Changed name
Ossuary Insane	United States	Death Metal	Split-up
Ossyris	Spain	Heavy Metal	Active
Ost Est Ima	Canada	Death Metal	Split-up
Ostakulo	Spain	Thrashcore	Split-up
Ostile	Italy	Power/Thrash Metal	Split-up
Ostitto	Bangladesh	Deathcore	Active
Ostots	Spain	Heavy Metal	Split-up
Ostots	Spain	Black Metal	Active
Ostpreussen	Poland	Death/Thrash Metal	Split-up
Ostracised	Netherlands	Black Metal	Split-up
Ostracized	France	Thrash/Death Metal	Split-up
Ostrog	Germany	Heavy Metal	Active
Ostrogoth	Australia	Black Metal	Split-up
Ostrogoth	Belgium	Heavy/Power Metal	Active
Ostrov	United States	Atmospheric Sludge Metal/Post-Hardcore	Active
OSV	United States	Progressive Metal	Active
Osvajaci	Serbia	Heavy Metal	Active
Oswenzim	Russia	NS Black Metal	Active
Osyris	Germany	Power Metal	Split-up
Otargos	France	Black Metal	Active
Otehi	Italy	Stoner/Doom Metal	Active
Otesanek	United States	Sludge/Drone Doom Metal	Split-up
Othendara	United States	Black Metal	On hold
Other Gods	Italy	Viking/Death Metal	Active
Other Side	Brazil	Heavy/Thrash Metal	Active
Other Side	Argentina	Heavy Metal	Active
Other View	Italy	Heavy Metal	Active
Other World	Italy	Heavy / Power Metal	Unknown
Otherside	Poland	Doom Metal	Split-up
Otherwise	Paraguay	Thrash Metal	Active
Othilan	Belarus	Black Metal	Active
Othis	Poland	Melodic Thrash Metal	Active
Othyrworld	Canada	Power/Progressive Metal	Active
Otila	Hungary	Gothic Metal / Rock	Split-up
Otis Driftwood	United States	Death Metal/Deathcore	Active
Otis Reaper	United States	Sludge Metal	Active
Otivm	Italy	Progressive Death Metal	Active
Otorium	Sweden	Death Metal	Active
Ottar	Indonesia	Gothic Metal	Unknown
Ottia	Mexico	Black/Death Metal	Active
Otuq	Peru	Black Metal	Active
Otus Scops	Austria	Symphonic Death Metal	Split-up
Otyg	Sweden	Folk Metal	Active
Oubliette	United Kingdom	Black Metal	Split-up
Oubliette	United States	Metalcore	Split-up
Ouija	Spain	Black Metal	Active
Ouija Ouitch	United States	Stoner/Doom Metal	Active
Oulanem	Chile	Black Metal	Active
Ounce of Self	United States	Heavy/Groove Metal	Active
Ounis	Poland	Thrash Metal	Split-up
Our Darkest Day	United States	Groove Metal/Metalcore	Active
Our Days Are Numbered	United States	Melodic Death Metal/Metalcore	Active
Our Diabolical Embrace	Canada	Symphonic Black/Gothic Metal	Active
Our Dying Concept	United Kingdom	Melodic Death/Thrash Metal/Metalcore	Split-up
Our Dying Souls	United States	Melodic Death Metal/Metalcore	Split-up
Our Fate in Hell	United States	Groove/Thrash Metal/Metalcore	Active
Our Final Chapter	United States	Death Metal/Grindcore	Split-up
Our Grace	France	Thrash/Death Metal	Split-up
Our Haunted Kingdom	United Kingdom	Doom/Death Metal (early), Stoner Metal (later)	Changed name
Our Lady of Bloodshed	Canada	Death Metal/Deathcore	Active
Our Malignant Beloved	United States	Technical Groove/Thrash Metal	Active
Our Renaissance	United States	Thrash/Death Metal/Metalcore	Split-up
Our Requiem	United Kingdom	Thrash/Death Metal	Unknown
Our Survival Depends on Us	Austria	Sludge/Doom Metal	Active
Ouroboros	Australia	Technical Death/Thrash Metal	Active
Ouroboros	Canada	Black Metal	Split-up
Ouroboros	France	Brutal Death Metal	On hold
Out Body Experience	Tunisia	Melodic Black/Doom Metal	Active
Out Comes the Storm	Netherlands	Thrash Metal/Metalcore	Active
Out for a Kill	Italy	Thrash/Heavy Metal	Active
Out for Blood	United States	Death Metal/Grindcore/Metalcore	Changed name
Out for Blood	United Kingdom	Metalcore/Sludge/Death Metal	Active
Out in the Cold	Belgium	Death Metal	Split-up
Out of Area	Germany	Melodic Heavy Metal	Active
Out of Channel	Russia	Melodic Death Metal/Metalcore	Active
Out of Damage	Germany	Heavy/Thrash Metal	Active
Out of Darkness	Canada	Death Metal	Split-up
Out of Enemies	United Kingdom	Death/Thrash Metal/Metalcore	Active
Out of Hatred	United States	Groove Metal/Deathcore	Split-up
Out of Memory	Hungary	Death Metal	Active
Out of Mind	Germany	Melodic Death Metal	Active
Out of Mind	Sweden	Death Metal	Split-up
Out of Mind	Germany	Traditional Heavy Metal	Split-up
Out of Mortality	United States	Death Metal	Active
Out of My Flame	Germany	Death Metal	Split-up
Out of Order	Germany	Power Metal	Active
Out of the Lair	Greece	Power Metal with Thrash Elements	Active
Out of the System	Netherlands	Thrash Metal	Changed name
Out of Yesteryear	Belarus	Melodic Death Metal/Deathcore	Active
Out on Guard	United States	Progressive Death Metal	Active
Out've the Box	United States	Heavy Metal/Hard Rock	Active
Outbreak	Sweden	Black Metal	Split-up
Outbreak	United States	Groove/Thrash Metal	Split-up
Outbreak	Canada	Thrash Metal	Split-up
Outbreak	United States	Thrash Metal	Split-up
Outbreak	Italy	Thrash Metal	Split-up
Outbreak Riot	Japan	Thrash Metal	Active
Outbreeding	Russia	Death Metal	Split-up
Outburst	Greece	Power/Speed Metal	Split-up
Outburst	Netherlands	Melodic Death/Thrash Metal	Active
Outburst	Japan	Death/Thrash Metal	Active
Outburst	France	Thrash Metal	Active
Outburst	United Kingdom	Stoner Metal	Active
Outburst	Finland	Heavy Metal	Split-up
Outburst on the 66	United States	Stoner Metal	Active
Outcast	Germany	Heavy Metal	Split-up
Outcast	Greece	Melodic Heavy Metal	Split-up
Outcast	Belgium	Death Metal	Active
Outcast	Chile	Melodic Death/Thrash Metal	Active
Outcast	Netherlands	Thrash Metal	Split-up
Outcast	France	Progressive Thrash/Death Metal	Active
Outcast	Switzerland	Thrash Metal	Split-up
Outcasts	United States	Thrash Metal	Split-up
Outcome	France	Deathcore	Active
Outcry	Cuba	Thrash Metal	Active
Outcry	Greece	Speed/Heavy Metal	Split-up
Outcry	Italy	Melodic Death Metal	Active
Outcryfire	United Kingdom	Thrash/Metalcore	Split-up
Outer Edge	Poland	Heavy Metal	Split-up
Outer Skin	Portugal	Heavy Metal/Hard Rock	Active
Outface	Greece	Progressive Thrash Metal	Split-up
Outgunned	United Kingdom	Thrash/Groove Metal	Active
Outlander	United States	Heavy Metal/Power Metal	Split-up
Outlast the Sun	United Kingdom	Thrash Metal/Crossover/Punk Rock	Active
Outlaw	United Kingdom	Thrash/Heavy Metal	Unknown
Outlaw Order	United States	Sludge Metal	On hold
Outliar	United States	Groove Metal	Active
Outloud	Canada	Thrash Metal	On hold
Outloud	Greece	Heavy Metal, Hard Rock	Active
Outlying	Canada	Thrash/Black Metal (early), Melodic Death Metal (later)	Active
Outrage	United States	Heavy Metal	Split-up
Outrage	Japan	Speed/Thrash Metal	Active
Outrage	Germany	Thrash Metal/Metalcore	Changed name
Outrage	United States	Heavy/Power Metal	Split-up
Outrage	Turkey	Death Metal	Split-up
Outrage	Austria	Death Metal	Active
Outrage	Italy	Thrash Metal	Split-up
Outrage	Canada	Thrash/Progressive/Speed Metal	Active
Outrage	United States	Thrash Metal	Active
Outrage	Germany	Blackened Thrash Metal	Active
Outrage	Canada	Speed/Thrash Metal	Split-up
Outrage	Finland	Thrash Metal	Split-up
Outrage	Australia	Thrash Metal	Split-up
Outrage	Canada	Death/Thrash Metal	Split-up
Outrage	Australia	Heavy Metal	Split-up
Outre-Tombe	Canada	Thrash/Speed Metal	Active
Outremer	Sweden	Doom/Stoner Metal	Active
Outset	Brazil	Death Metal/Grindcore	Active
Outshine	Portugal	Progressive Metal	Split-up
Outshine	Lithuania	Melodic Metal	Split-up
Outshined	United Kingdom	Melodic Groove/Thrash Metal	Split-up
Outside	Germany	Heavy Metal	Active
Outside	Japan	Heavy Metal	Active
Outsider	Bulgaria	Thrash Metal	Split-up
Outsider	Lithuania	Death Metal	Split-up
Outsider	Italy	Thrash Metal	Active
Outsider	Czech Republic	Heavy Metal	Split-up
Outspan	Switzerland	Heavy Metal/Hard Rock	Split-up
Outta Hand	United States	Heavy Metal	Split-up
Outta Line	United States	Heavy Metal	Split-up
Outward Ceremony	France	Black Metal	Split-up
Outworld	United States	Progressive Heavy/Speed Metal	Split-up
Ov	United States	Black/Death Metal	Active
Ov Dust	United States	Black/Thrash Metal	Active
Ov Hell	Norway	Black Metal	Active
Ov Hollowness	Canada	Atmospheric/Ambient Black Metal	Active
Ovall	United States	Progressive Metal	Active
Ovaryrot	United States	Brutal Death Metal/Goregrind	Active
Over	Italy	Melodic Thrash Metal	Active
Over Blood	Colombia	Thrash Metal	Active
Over Dead In Over	Italy	Thrash/Death Metal	Active
Over Death	Indonesia	Brutal Death Metal	Unknown
Over Dose	Japan	Thrash Metal	Split-up
Over Hole	Japan	Crossover/Groove/Thrash Metal	Unknown
Over My Grave	Argentina	Gothic Metal	Split-up
Over Nation	Italy	Thrash Metal	Active
Over Rage	Brazil	Thrash Metal	Active
Over Reaction	Colombia	Thrash Metal	Active
Over Ride	Japan	Power Metal	Active
Over Speed	Brazil	Thrash Metal	Unknown
Over the Coals	Canada	Thrash Metal	Active
Over the Edge	Netherlands	Thrash Metal	Split-up
Over the Top	United States	Speed/Thrash Metal	Split-up
Over Us Eden	International	Progressive Metal	Active
Over Your Threshold	Germany	Death/Thrash Metal (early), Progressive Death Metal (later)	Active
Overaction	Brazil	Heavy Metal	Split-up
Overage	Italy	Heavy Metal	Split-up
OverBlack	India	Melodic Death/Thrash Metal	Active
Overblood	Italy	Groove/Post-Thrash Metal	Active
Overbreath	Finland	Crossover/Thrash Metal	Active
Overcast	Greece	Thrash Metal/Crossover	Split-up
Overcast	Hungary	Doom/Death Metal (early), Doom Metal (later)	Active
Overcast	United States	Metalcore	Active
Overdawn	Bulgaria	Melodic Death Metal/Metalcore	Active
Overdeth	Sweden	Power Metal	Active
Overdose	France	Speed/Thrash Metal	Split-up
Overdose	Italy	Thrash Metal	Split-up
Overdose	Germany	Heavy Metal	Split-up
Overdose	United States	Thrash Metal	Changed name
Overdose	Germany	Heavy Metal	Split-up
Overdose	Brazil	Power/Thrash, Groove Metal	On hold
Overdoze	Finland	Thrash Metal	Active
Overdream	Hungary	Symphonic Power Metal	Active
Overdrive	United Kingdom	NWOBHM	Active
Overdrive	Argentina	Progressive Metal	Active
Overdrive	United States	Melodic Power Metal	Split-up
Overdrive	Mexico	Southern Metal	Active
Overdrive	Sweden	Heavy Metal	Active
Overdriver	Argentina	Heavy Metal	Active
Overdrunk	Canada	Heavy Metal	Active
OverFaith	Italy	Thrash Metal	Active
Overfiend	Germany	Black Metal	Changed name
Overfiend	Germany	Power Metal	Unknown
Overflash	Sweden	Death Metal (early), EBM-Gothic Metal (later)	Active
Overgard	Germany	Black Metal	Split-up
Overgarven	Greece	Death Metal	Active
Overground	Venezuela	Melodic Death Metal	Active
Overhate	Venezuela	Thrash Metal	Active
Overhead	Portugal	Thrash Metal	Split-up
Overheat	Sweden	Heavy Metal	Split-up
Overheat	Germany	Thrash/Power Metal	Split-up
Overkill	United Kingdom	NWOBHM	Split-up
Overkill	Germany	Heavy Metal	Split-up
Overkill	United States	Thrash Metal, Groove Metal	Active
Overkill	Germany	Heavy Metal	Split-up
Overkill	Sweden	Heavy Metal	Split-up
Overkrass	Spain	Groove/Thrash Metal	Active
Overlander	France	Progressive Thrash/Death Metal	Changed name
Overlife	Spain	Progressive Heavy Metal	Split-up
Overload	Switzerland	Heavy Metal	Split-up
Overload	Sweden	Heavy Metal	Active
Overload	Sweden	Heavy Metal	Split-up
Overload	France	Power Metal	Split-up
Overload	Italy	Crossover/Groove/Death Metal	Split-up
Overload	France	Thrash Metal	Split-up
Overload	Germany	Thrash Metal	Active
Overload	Hungary	Heavy Metal	Active
Overload	Canada	Death/Thrash Metal	Split-up
Overload	Poland	Heavy Metal	Split-up
Overload	Poland	Heavy/Groove Metal	Active
Overload	Brazil	Thrash/Heavy Metal	Changed name
Overload	France	Melodic Death Metal	Active
Overload	Croatia	Heavy Metal with Thrash Metal influences	Split-up
Overload	Greece	Traditional Heavy/Power Metal	Active
Overloaded	United States	Traditional Heavy Metal	Active
Overlook	Brazil	Thrash Metal	Active
Overlord	United States	Heavy Metal	Split-up
Overlord	Brazil	Power Metal	Split-up
Overlord	Canada	Heavy Metal with Doom Elements	Active
Overlord	Croatia	Death/Thrash Metal	Split-up
Overlord	United Kingdom	Melodic Death/Thrash Metal	Active
Overlord	Sweden	Heavy Metal	Split-up
Overlord	Paraguay	Thrash Metal	Split-up
Overlord	Serbia	Epic Black Metal	Active
Overlord	Poland	Death Metal	Split-up
Overlord	Sweden	Death Metal	Split-up
Overlord	United States	Traditional Metal	Split-up
Overlord	Germany	Death/Thrash Metal	Split-up
Overlord	United States	Death/Thrash Metal	Split-up
Overlord Exterminator	United States	Black Metal	Unknown
Overlord Industries	Sweden	Death Metal	On hold
Overlorde	United States	Traditional Metal	Active
Overlorde SR	United States	Traditional/Power Metal	Active
Overmars	France	Sludge Metal	Active
OverMaster	Italy	Heavy/Power Metal	Active
Overmeind	Germany	Gothic Metal	Split-up
Overmind	Poland	Heavy/Thrash Metal	Split-up
Overmind's Curse	Greece	Psychedelic Doom/Death Metal	Active
Overnoise	Brazil	Thrash Metal	Split-up
Overoth	United Kingdom	Death Metal	Active
Overpast	Ukraine	Gothic/Industrial/Doom Metal	Unknown
Overproof	United Kingdom	Southern/Thrash Metal	Active
Overproof Groove	Australia	Thrash/Groove Metal	Active
Overrain	Italy	Thrash Metal	Active
Override	Greece	Thrash/Death/Black Metal	Changed name
Overrider	United Kingdom	Heavy/Doom/Stoner Metal	Split-up
Overrun	Finland	Death/Thrash Metal	Unknown
Overseer	United States	Death Metal	Split-up
Overshadow	Brazil	Heavy/Progressive Metal	Split-up
Oversight	Greece	Heavy/Power Metal	Split-up
Oversoul	France	Groove Metal/Hardcore	Split-up
Oversoul	United States	Doom/Progressive Metal	Split-up
Overstatement	Portugal	Thrash Metal	Active
Overstep	France	Heavy Metal	Active
Overstolz	Germany	Death/Thrash Metal	Split-up
Overt Enemy	United States	Thrash Metal	Split-up
Overt Hostility	Finland	Death Metal	Unknown
Overtake	Finland	Heavy / Thrash Metal	Active
Overthrash	Brazil	Thrash Metal	Split-up
Overthrash	Brazil	Thrash Metal	Split-up
Overthrone	United States	Black Metal	Split-up
Overthrow	Chile	Death Metal	Split-up
Overthrow	Canada	Death/Thrash Metal	Split-up
Overthrow	Norway	Heavy/Thrash Metal	Active
Overthrow	Argentina	Death Metal	Split-up
Overthrowing	Colombia	Black/Death Metal (early), Death Metal (later)	Active
Overtone	United States	Heavy/Doom Metal	Split-up
Overture	Brazil	Heavy Metal	Unknown
Overture	United States	Progressive Metal	Split-up
Overture	United States	Death Metal	Active
Overture	Germany	Gothic/Death Metal	Split-up
Overtures	Italy	Melodic Heavy Metal	Active
Overvibes	United Kingdom	Heavy/Thrash Metal	Split-up
Ovif	Canada	Thrash Metal	Active
Ovnengard	Germany	Black Metal	Unknown
Ovoian	United States	Thrash Metal	Active
Ovroboros	Chile	Death Metal	Active
Ovskum	Italy	Black Metal	Active
Ovskum/Morke	Italy	Black Metal/Ambient/Drone	Active
Ovvercross	Brazil	Power/Speed Metal	Split-up
Owen Hart	United States	Black Metal/Grindcore	Changed name
Owl	Germany	Death Metal	Active
Owl	United States	Heavy/Stoner/Doom Metal	Active
Owl Witch	United States	Thrash/Death Metal	Active
Owl's Blood	Spain	Black Metal	Active
Owlscry	United States	Black Metal	Active
Ownbliss	Slovakia	Metalcore	On hold
Ox	Canada	Drone/Doom Metal	Unknown
Ox vs. Thunderbird	United States	Sludge/Doom Metal	On hold
Oxblood	Greece	Thrash/Death Metal	Split-up
Oxbow	United States	Stoner/Doom Metal, Avant-garde	Active
Oxenkiller	France	Heavy Metal	Split-up
Oxidation	United States	Thrash Metal	Active
Oxide	Poland	Thrash Metal	Split-up
Oxidised Razor	Mexico	Grindcore	Active
Oxidized Faith	Canada	Technical Death Metal	Active
Oxidizer	Brazil	Thrash Metal	Split-up
Oxido	Argentina	Heavy Metal	Active
Oxido	Peru	Heavy Metal	Unknown
Oxiplegatz	Sweden	Symphonic/Post-Black Metal	Split-up
Oxizor	Chile	Heavy Metal	Split-up
Oxlahun	Mexico	Death Metal	Split-up
Oxnkiller	Germany	Death Metal/Grindcore	Split-up
OxNx	Japan	Death Metal/Grindcore	Changed name
Oxus	Mexico	Thrash / Death Metal	Active
Oxxo Xoox	France	Doom/Gothic Metal	Active
Oxyacanthous	United Kingdom	Experimental Death Metal	Split-up
Oxyde	France	Thrash Metal	Changed name
Oxym	United Kingdom	NWOBHM	Split-up
Oxymor	France	Black Metal	Active
Oxyrius	France	Death/Thrash Metal	Split-up
Oyabun	France	Stoner Metal/Rock	Active
Oyarsa	Costa Rica	Progressive Death Metal	Active
Oyhra	Belarus	Pagan Black Metal	Split-up
Oz	Finland	Heavy Metal	Active
Ozirisz	Hungary	Heavy Metal	Active
Ozlomoth	France	Black Metal	Unknown
Ozmio	Mexico	Thrash/Groove Metal	Active
Ozon	Malaysia	Hard Rock/Heavy Metal	Split-up
Ozone	Austria	Heavy Metal/Hard Rock	Split-up
Ozzy Osbourne	United Kingdom	Heavy Metal	Active
The O-Larn Project	Thailand	Heavy Metal (early), Pop/rock (later)	Active
The Oath	France	Black/Death Metal	Active
The Oath	United States	Black Metal	Active
The Obliterate Plague	United States	Dark Metal	Active
The Obscene	United Kingdom	Death Metal	Active
The Obscene	Sweden	Heavy Metal	Split-up
The Obsessed	United States	Doom Metal	Active
The Obsidian	Spain	Atmospheric Doom Metal	Split-up
The Ocean	Germany	Progressive/Atmospheric Sludge Metal/Post-Hardcore	Active
The Ocean Walker	United States	Technical Progressive Deathcore	Active
The Odours	Poland	Death Metal/Grindcore	Active
The Odyssey Project	United States	Progressive Rock/Metal	Active
The Ogre Oak	Germany	Black/Death Metal	Active
The Old Dead Tree	France	Gothic Metal	Split-up
The Old Four	Czech Republic	Thrash/Groove Metal	Active
The Old Ones	Czech Republic	Heavy Metal	Active
The Ollogy	Australia	Progressive Metal	Unknown
The Olsen's Crypt	Spain	Raw Black Metal	Changed name
The Omen	Australia	Thrash Metal	Active
The One	Greece	Black Metal	Active
The Onslaught	United States	Thrash/Death/Groove Metal	Changed name
The Opera	Italy	Power/Progressive Metal	Active
The Ophidian Ascension	Australia	Death Metal	Active
The Oppressor	United States	Death Metal	Active
The Orchid's Curse	Canada	Melodic Death/Groove/Metalcore	Active
The Orcus	Estonia	Symphonic Power Metal	Split-up
The Ordeal	Germany	Power/Heavy Metal	Active
The Order	Switzerland	Melodic Heavy Metal	Active
The Order	Romania	Groove/Thrash Metal	Split-up
The Order of Apollyon	United Kingdom	Black/Death Metal	Active
The Order of Chaos	Canada	Heavy/Power/Thrash Metal	Active
The Order of Chaos	Greece	Black Metal	Active
The Order of Retribution	United States	Experimental Dark Ambient/Black Metal	Active
The Ordher	Brazil	Death Metal	Split-up
The Organization	United States	Heavy Metal/Hard Rock	Split-up
The Orphan & The Widow	United States	Black metal	Active
The Osedax	United States	Sludge/Doom Metal	Active
The Other Dimension	Germany	Melodic Death/Black Metal	Split-up
The Other Side	Poland	Doom Metal	Split-up
The Other Side	Brazil	Heavy Metal	Active
The Other Side of the Sky	United States	Sludge Metal/Ambient	On hold
The Ottoman Empire	United States	Progressive Metal	Changed name
The Outburst	France	Melodic Thrash/Post-Thrash Metal	Split-up
The Outcast	United States	Thrash Metal	Split-up
The Outside	Germany	Thrash Metal	Active