O

OAK (Norway – Progressive Rock)

OATHSWAN (Greece – Alternative Metal)

OBELISK (Scotland – Metalcore)

OBLIVION GATE (Finland – Gothic Rock)

OBLIVION VOYAGE (Portugal – Death Metal)

OB NIXILIS (USA – Black Metal)

OBSCURUS REX (Greece – Heavy Metal)

OBSERVE THE 93RD (USA – Alternative Metal)

THE OBSIDIAN RESURRECTION (USA – Symphonic Extreme Metal)

OCEAN ASYLUM (USA – Math Rock)

OCEAN’S EDGE (Greece – Progressive Metal)

OCEAN OF LOTION (Norway – Synth Pop/Rock)

OCTALUX (USA – Heavy Metal)

ODC (France – Metalcore)

OF SPITE (Finland – Death Metal)

OF VIRTUE (USA – Metalcore)

OF VIZIONS (USA – Rock)

OHMWORK (Norway – Heavy Metal)

THE OKLAHOMA KID (Germany – Progressive Metalcore)

OLAOUTO (Greece – Alternative Rock)

OLATHIA (USA – Thrash Metal)

OLD DIRTY BUZZARD (USA – Hard Rock)

OLIVE DARES THE DARKNESS (USA – Alternative Rock)

OMNIVORTEX (Finland – Death Metal)

ONCE UPON A WINTER (Greece – Post-Metal)

ONCHOCERCIASIS ESOPHAGOGASTRODUODENOSCOPY (Canada – Brutal Death Metal)

ONE MORNING LEFT (Finland – Metalcore)

ONIOROSHI (Italy – Progressive Metal)

OPEN SURGERY (Sweden – Death Metal)

THE OPTIMIST IN ME (Netherlonds – Alternative Rock)

ORAGE (Germany – Heavy Metal)

ORANGE CREEK RIDERS (USA – Alternative Rock)

ORCHID’S CURSE (Canada – Metalcore)

ORION (England – Progressive Rock)

ORO (Sweden – Post/Sludge-Metal)

THE ORPHANED BEE (Australia – Synth Rock)

ORPHAN SKIN DISEASES (Italy – Rock)

ORYAD (USA – Symphonic Metal)

OUDEZIEL (Poland – Post-Rock)

OUR DYING WORLD (USA – Thrash Metal)

OUR HOLLOW OUR HOME (England – Metalcore)

OUR MIRAGE (Germany – Post-Hardcore)

OUR NORTH (England – Metalcore)

OUTLYING (Canada – Melodic Death Metal)

OUTRUN THE DAY (England – Doom Metal)

OVDETH (Finland – Death Metal)

OVERCAST RAIN (Latvia – Symphonic Metal)

OVERSENSE (Germany – Melodic Metal)

OXIDIZE (Sweden – Heavy Metal)

OZUL (Norway – Progressive Rock)