Bands

Obsequies

United States · Black Metal

Obsidian Spine

United States · Black/Death Metal

Ocean of Ghosts

United States · Drone/Funeral Doom Metal/Dark Ambient/Shoegaze

Ocean of Obsession

United States · Progressive/Melodic Death Metal/Deathcore

Odar

United States · Raw/Depressive Black Metal

Old Moon

United States · Black Metal

Old Moon

United States · Melodic Black Metal

Ominous Hymn

United States · Black Metal

One Master

United States · Black Metal

OnlyGodIsPerfect

United States · Raw Black Metal/Noise

On Paths of Torment

United States · Melodic Death Metal/Metalcore

Onslaught

United States · Thrash Metal

Onward We March

United States · Groove Metal/Metalcore

Opaque Trials

United States · Atmospheric/Depressive Black Metal

Oppressive Descent

United States · Black Metal

Optimist

United States · Depressive Black Metal

Orange Diesel

United States · Stoner Metal/Rock

Organ Dealer

United States · Grindcore

Organharvest

United States · Brutal Death Metal

Oroku Saki and the Foot

United States · Experimental Death Metal/Grindcore

Orosius

United States · Black Metal

Orphan Crippler

United States · Blackened Death Metal

Ossiculum

United States · Funeral Doom/Death Metal

Otalgia

United States · Black Metal