Bands
O, Majestic Winter
Experimental Black Metal · Lewisburg, TN
Obeisance
Thrash/Black Metal · El Paso, TX
Disbanded
Object of Aggression
Death Metal/Metalcore · Atlanta, GA
Oblatory
Brutal Death Metal · Dallas, TX
Disbanded
Obliquity
Death Metal · Houston, TX
Disbanded
Obliteration X
Death Metal · Aransas Pass, TX
Oblivion Circle
Melodic Black/Death Metal/Metalcore · Fort Worth, TX
Disbanded
Oblivious Obscurity
Death Metal · Dallas, TX
Obscure Oracle
Melodic Black/Death Metal · San Angelo, TX
Disbanded
Obscurum
Black Metal · Atlanta, GA
Obsecrate the Deity
Technical Death Metal · Atlanta, GA
Disbanded
Obsidian
Heavy Metal · Dallas/Fort Worth, TX
Disbanded
Obsidian Throne
Melodic Death Metal · Fort Worth, TX
Ocanthus
Gothic/Melodic Doom Metal · Arlington, TX
Occulsed
Death Metal · Atlanta, GA
Disbanded
Ocean Architecture
Progressive Metal/Rock · Murfreesboro, TN
Oceans of Slumber
Progressive Metal/Rock · Houston, TX
October Noir
Gothic/Doom Metal · Pensacola, FL
Oculus of Profanations
Death Metal · Del Rio, TX
Disbanded
Odious
Thrash Metal · Arlington, TX
Disbanded
Of Allegiance
Thrash/Doom Metal · Grand Prairie, TX
Of Forsaken Divinity
Experimental Ambient Black Metal · Weslaco, TX
Disbanded
Of Serpents
Melodic Death Metal/Metalcore · Nashville, TN
Of the Fallen
Melodic Deathcore/Death Metal · Houston, TX
Disbanded
Ogre Upstairs
Progressive Thrash Metal · Hattiesburg, MS
Oh, the Depth
Symphonic Deathcore · Houston, TX
Disbanded
Omean
Sludge / Doom Metal · New Orleans, LA
Disbanded
Omega Thesis
Technical Doom Metal · Dallas/Fort Worth, TX
Omega Tribe
Thrash/Groove Metal · Bristol, TN
Omen of Death
Black Metal/Ambient · Conroe, TX
OmenBringer
Stoner Metal/Rock · Nashville, TN
Omission
Thrash Metal/Crossover · Dallas, TX
Disbanded
Omnibane
Sludge Metal/Hardcore · Little Rock, AR
Omnimorph
Post-Metal · Denton, TX
OmniTerror
Death Metal · Fort Worth, TX
Omotai
Progressive Sludge Metal · Houston, TX
On Neginoth
Black Metal, Ambient · Nashville, TN
Disbanded
One Last Torture
Groove/Death/Nu-Metal/Metalcore · Houston, TX
One We Created
Technical Death Metal/Deathcore · San Antonio, TX
Open Kasket
Death Metal/Hardcore · Little Rock, AR
Opium
Death Metal / Grindcore · Tupelo, MS
Disbanded
Oppressive Force
Brutal Death Metal/Grindcore · San Antonio, TX
Orangutan Juice
Sludge/Stoner/Doom Metal · Corpus Christi, TX
Orcanaut
Progressive Stoner/Sludge Metal · Denton, TX
Disbanded
Orchiectomy
Brutal Death Metal/Goregrind · Houston, TX
Orcrist
Disbanded
Symphonic Black Metal · Georgia
Order of Bileth
Black Metal · Mission, TX
Order of the Owl
Sludge/Stoner Metal · Atlanta, GA