Bands whose names start with 'O'

Oathean,  a black metal band from South Korea
Obituary,  a death metal band from Brandon, FL, USA
Obliveon,  a thrash metal band from Montreal, QC, Canada
Obscene Gesture,  a thrash metal/crossover band from Los Angeles, CA, USA
Obscura,  a death metal band from Munich, Germany
The Obsessed,  a doom metal band from MD, USA
Obsession,  a 80's metal band from New Haven, CT, USA
Obtained Enslavement,  a black metal band from Norway
Obtest,  a black metal band from Vilnius, lt
Occult,  a thrash metal band from Netherlands
Ocean,  a band from France
Ocean Machine,  a band from Canada
Oceans Of Sadness,  a gothic metal band from Belgium
Octavia Sperati,  a gothic metal band from Bergen, Norway
October 31,  a traditional metal band from Arlington, VA, USA
October Tide,  a doomdeath band from Sweden
Odin,  a hard rock band from Los Angeles, CA, USA
Of Rytes,  a thrash metal band from Frankfurt, Germany
Officium Triste,  a doomdeath band from Netherlands
Ogre,  a band from . (page not yet online)
Oil,  a christian metal band from Los Angeles, CA, USA
Old,  a thrash metal band from Germany (page not yet online)
Old,  a band from USA
The Old Dead Tree,  a band from France (page not yet online)
Old Funeral,  a death metal band from Norway
Old Man's Child,  a melodic death metal band from Norway
Old Yron,  a band from Italy (page not yet online)
Oliver Magnum,  a 80's metal band from OK, USA
Olympos Mons,  a power metal band from Hanko, Finland
Om,  a stoner rock band from Oakland, CA, USA
Omega,  a nwobhm band from London, England
Omen,  a 80's metal band from Los Angeles, CA, USA
Omnitron,  a thrash metal band from Sweden
Omnium Gatherum,  a death metal band from Finland
Once Dead,  a christian metal/thrash metal band from USA (page not yet online)
OnceOver,  a band from USA (page not yet online)
One Man Army And The Undead Quartet,  a thrash metal band from Sweden
One Minute Silence,  a rap metal band from London, England
One-Way Mirror,  a metalcore band from France
Only Living Witness,  a band from MA, USA (page not yet online)
Onslaught,  a thrash metal band from England
On Thorns I Lay,  a band from Greece
Onward,  a power metal band from USA
Opera IX,  a black metal band from Italy
Opeth,  a death metal band from Sweden
Ophthalamia,  a black metal band from Sweden
Ophydian,  a metalcore band from Turin, Italy
Opposite Earth,  a progressive metal band from Tampa, FL, USA
Oppressor,  a death metal band from Chicago, IL, USA
Opprobrium,  a death metal band from LA, USA
Oracle,  a power metal band from Jacksonville, FL, USA
Orange Goblin,  a stoner rock band from England
Orden Ogan,  a power metal band from Germany
Order Of Ennead,  a death metal band from Tampa, FL, USA
Order Of Nine,  a power metal band from Pittsburgh, PA, USA
The Organization,  a band from San Francisco, CA, USA
Origin,  a death metal band from Topeka, KS, USA
Original Sin,  a thrash metal band from New York, NY, USA
Orodruin,  a doom metal band from Rochester, NY, USA
Orphanage,  a doomdeath band from Netherlands
Orphaned Land,  a death metal band from Israel
O.S.I.,  a progressive metal band from USA
Osiris,  a progressive metal band from Netherlands
Ossian,  a traditional metal band from Hungary
Ostrogoth,  a 80's metal band from Ghent, Belgium
Otep,  a nu-metal band from Los Angeles, CA, USA
Othyrworld,  a band from Canada
Outrage,  a thrash metal band from Nagoya, Japan
Outworld,  a progressive metal band from Houston, TX, USA
Ov Hell,  a black metal band from Norway
Overdose,  a thrash metal band from Belo Horizonte, Brazil
Overdrive,  a 80's metal band from Sweden
Overkill,  a thrash metal band from New York, NY, USA
Overkill,  a thrash metal band from Los Angeles, CA, USA
Overlorde,  a 80's metal band from NJ, USA
Overmars,  a atmospheric hardcore band from Lyon, France
Oversoul,  a doom metal band from Shawnee, OK, USA
Ovif,  a thrash metal band from Montreal, QC, Canada
Oxenkiller,  a 80's metal band from France
Oz,  a 80's metal band from Nakkila, Finland
Ozzy Osbourne,  a band from England