October Thorns

October Tide

Odious Mortem

Odious Sanction

Odium Humani Generis

Of Feather and Bone

Of Mice & Men

Ofdrykkja

Officium Triste

Officium Triste (Netherlands)

Oh Hiroshima

OJ Flynn

Old Forest

Old Funeral

Old Man's Child

Old Wolf

Olkoth

Omen

Ominous Scriptures

Omnihility

Omnisium

Omophagia

On Sale

On Thorns I Lay

Ona Snop

Once Human

Oncology

Ondfødt

One Desire

One-Way Mirror

Oneheil

Onesie

Onheil

Oni

Onslaught

Ontborg

Onward With Love

Open The Nile

Operation Ivy

Opeth

Ophthalamia

Oranssi Pazuzu

ORB

Orbit Culture

Orchid

Organ Dealer

Organectomy

Óreiða