Oldenblood Productions

Canada

Ole Crow Records

USA

Olegcorec

unknown

Olifant Records

Poland

Oliver Records

Brazil

Olivia Records

Italy

Olog Productions

Russia

Olympic Disk

France

Olympic Recordings

USA

Olympus Mons Records

Germany

Olympus Records (Bootleg)

Unknown

OM Discos

Colombia

OMC De Laudun L'Ardoise

France

OMC Records

USA

Omega Music

Poland

Omega Productions

Belarus

Omega Records

Germany

Oméga Studio

unknown

Omega Warfare Records

United-Kingdom

OmegaWave Records

Indonesia

Omen Records (Bootleg)

Unknown

Omerta

unknown

Omeyocan Productions

Mexico

OMF Records

USA

Omicron Music Productions

Greece

Ominous Productions

Finland

Ominous Radiance Records

Greece

Ominous Recordings

Sweden

Ominous Silence Records

Ireland

Omn Label Services

unknown

Omnicult Records

Finland

Omnipresence Productions

Norway

Omniversal Records

Austria

OMP Producciones

Paraguay

OMR Series

unknown

OMS Records

Ukraine

OMV Records

Canada

Omvina

Germany

On A Faim!

France

On Air Media Reflex

Turkey

On Air Records

unknown

On Air!

unknown

On Dead Sound

Italy

On Fire Records

Spain

On Line Records

Poland

On My Own Records

Finland

On Oath

unknown

On Parole Productions

Slovenia

On Records

unknown

On Stage Records

Italy

On The Camper Records

Switzerland

On The Air

unknown

On The Attack Records

USA

On The Go Music

USA

On The Rise Records

USA

On The Road

unknown

On The Verge Records

United-Kingdom

On-Line Indie Label

unknown

On-U Sound

unknown

Onbekend

unknown

Once Bitten Music (OBM)

United-Kingdom

One Armed Man Records

Croatia

One Armed Productions

USA

One Brick Today

Australia

One Coin Records

Japan

One Day Savior

USA

One Eye Records

USA

One Eyed Toad Records

United-Kingdom

One Fear Records

unknown

One Life One Crew Records

Germany

One Life Recordings

Brazil

One Little Indian

United-Kingdom

One Massive Joint

Philippines

One Million Dead

USA

One Music Records

South-Korea

One People One Struggle Records

Germany

One Percent Records

USA

One Person Party

France

One Records

Serbia

One Rpm

USA

One Scene Unity Records

France

One Sock Records

USA

One Step Ahead Records

USA

One String Short Records

unknown

One Thousand Days In Sodom

Netherlands

One Voice Asia

Singapore

One Voice Recordings

Netherlands

One Voice Records

Brazil

One Way Records

USA

One Wild Collective

France

One World Communications

USA

One-A Records

Japan

One-Up

United-Kingdom

Oneiric Terror

Greece

OneManArmy Records

unknown

Oneseventwo Records

Malaysia

OneVision

unknown

OnEye Records

Brazil

Onfire

unknown

Onge Records

Germany