| Artists | Songs | Original Artists | Albums |
|---|---|---|---|
| Obituary | Buried Alive | Venom | Anthology/CD//RR |
| Obituary | Circle Of The Tyrants | Celtic Frost | Cause Of Death/CD/1991/RR |
| Obscenity | Raining Blood | Slayer | Human Barbecue/CD/1998 |
| Obscura | God Of Emptiness | Morbid Angel | Retribution/CD/2006 | 2010 Remastered edition |
| Obscura | Lack of Comprehension | Death | Retribution/CD/2006 |
| Obscura | Synthetically Revived | Suffocation | Retribution/CD/2006 | 2010 Remastered edition |
| Obscura | Wings | Vader | Live |
| Obtruncation | Dead Shall Rise | Terrorizer | Live |
| Occult | Jaws Of Satan | Sathanas | |
| Ocean Of Sorrow | Without God | Katatonia | Mystery of Winter/CD/2005 |
| October 31 | Child Of The Damned | Warlord | Voyage To Infinity/Demo/1996 |
| October 31 | Electric Eye | Judas Priest | Salem's Curse/Single/2002 |
| October 31 | Give 'em The Axe | Lizzy Borden | Visions Of The End/EP/1998 |
| October 31 | Harder Than Steel | Jag Panzer | Visions Of The End/EP/1998 |
| October 31 | Missing In Action | Q5 | Powerhouse/Single/2005 |
| October 31 | Public Enema Number 1 | Iron Maiden | A Call to Irons 2/TCD |
| October 31 | Wrecking Crew | Overkill | No Survivors/CD/2005 |
| Officium Triste | Head Stone | Chorus Of Ruin | Roses On My Grave/EP/1999 |
| Officium Triste | Love Like Blood | Killing Joke | Charcoal Hearts/CD/2009/Dis |
| Officium Triste | Sleepless | Anathema | [Live] |
| Offspring | Hey Joe | Jimi Hendrix | Go Ahead Punk... Make My Day/CCD |
| Offspring | Killboy Powerhead | Didjits | Smash |
| OLD | Cocaine | Cream | Old Lady Drivers/CD |
| OLD | Who Are You? | Black Sabbath | Eternal Masters/TCD//Pri
Masters Of Misery/TCD/1992/Ear | Japan, US Mosh 100/Box/1995/Ear |
| Omala | FX | Black Sabbath | The Legacy 1990/TCD//FF |
| Omen | Radar Love | Golden Earring | Escape To Nowhere |
| Omen | Whole Lotta Rosie | AC/DC | Nightmares |
| Omnitron | Symptom Of The Universe | Black Sabbath | The Legacy 1990/TCD//FF |
| One Way System | Cum On Feel The Noize | Slade | |
| Onslaught | Atomic Punk | Van Halen | Welcome To Dying/EP/1989 |
| Onslaught feat. Tom Angelripper and Phil Campbel | Bomber | Motörhead | Sounds Of Violence/CD/2011 |
| Onslaught | Confused | Angel Witch | In Search of Sanity/CD/1990/ | CD bonus |
| Onslaught | Let There Be Rock | AC/DC | In Search of Sanity/CD/1990/ |
| Onslaught | Nice'n Sleazy | The Stranglers | Welcome To Dying/EP/1989 |
| On Target | Supernaut | Black Sabbath | The Legacy 1990/TCD//FF |
| Opera IX | One Rode To Asa Bay | Bathory | Anphisbena/CD/2004/AG |
| Opera IX | Rime Of The Ancient Mariner | Iron Maiden | Call to Irons/TCD |
| Opeth | Circle Of The Tyrants | Celtic Frost | In Memory Of Celtic Frost/TCD/1996 |
| Opeth | Death Metal | Possessed | Demo '91/Demo/1991 |
| Opeth | Remember Tomorrow | Iron Maiden | Call to Irons/TCD |
| Opeth | Soldier of Fortune | Deep Purple | Ghost Reveries/CD/2005/RR | Re-release |
| Ophthalamia | Deathcrush | Mayhem | Nordic Metal/CCD/1996
Via Dolorosa/CD/1995/AG |Bonus |
| Ophthalamia | Sacrifice | Bathory | To Elisha/CD
In Conspiracy With Satan/TCD/1998/Hellspawn |
| Ophthalamia | Songs Of Satan | Venom | A Long Journey/CD/1994 |
| Oppressor | Looks That Kill | Motley Crue | European Oppression Live + As Blood Flows/CD/1995 |
| Orange Coblin | Hand Of Doom | Black Sabbath | Nuclear Guru/EP |
| Orchestral Pit's Cannibals | Zodiac | Macabre | Alienthesis/CD/1996 |
| Order From Chaos | Nuctemeron | Sodom | Homage to the Gods/TCD/1999/Drakkar |
| Order of the Eibon Hand | A Fine Day To Die | Bathory | Hellas Salutes the Vikings/TCD/1997/ |
| Order of the Eibon Hand | Oden's Ride Over NordLand | Bathory | Hellas Salutes the Vikings/TCD/1997/ |
| Original Sin | Symptom of the Universe | Black Sabbath | Temptation
Ozzified/TCD |
| Osdorp Posse And Nembrionic Hammerdeath | Geen Slaap Tot Osdorp {No Sleep Till Brooklyn} | Dutch Lyrics | Beastie Boys | Hardcore Leeft/EP |
| Otyg | Holy Diver | Dio | Sagovindars Bonning/CD/1999 |
| Outrage | Blitzkrieg | Ramones | The Great Blue/CD/1990/PY |
| Outrage | I Feel Alright | Iggy Pop | The Great Blue/Cd/1990/PY |
| Oven & Stove | Paranoid | Black Sabbath | The Legacy 1990/TCD//FF |
| Overkill | Changes | Black Sabbath | Coverkill/CD/1999/CMC |
| Overkill | Cornucopia | Black Sabbath | The Killing Kind/CD// | Japan, Ltd Ed
Mega Kill Pack/// |
| Overkill | Deuce | Kiss | Coverkill/CD/1999/CMC |
| Overkill | Fuck You | DOA | Or Subhumans? | Fuck You/EP |
| Overkill | Heaven And Hell | Black Sabbath | WFO/CD | Hidden |
| Overkill | Hole In The Sky | Black Sabbath | Fuck You/EP | Re-release, Live
Rotten To The Core - The Demos | Live |
| Overkill | Hymn 43 | Jethro Tull | Coverkill/CD/1999/CMC |
| Overkill | Never Say Die | Black Sabbath | Coverkill/CD/1999/CMC |
| Overkill | No Feelings | Sex Pistols | Coverkill/CD/1999/CMC |
| Overkill | Overkill | Motorhead | Coverkill/CD/1999/CMC |
| Overkill | Sonic Reducer | Dead Boys | Into The Megavault Part One
Overkill/EP |
| Overkill | Space Trackin' | Deep Purple | Coverkill/CD/1999/CMC |
| Overkill | The Ripper [?] | Judas Priest | WFO/CD | Hidden |
| Overkill | Tyrant | Judas Priest | Judas Priest - Legends Of Metal II/TCD/1996/CM
The Killing Kind/CD//CD | [Ltd Ed] |
| Overkill | Under the Influence | Ramones | Coverkill/CD/1999/CMC |
| Overkill | War Pigs | Black Sabbath | Ten Years Of Wrecking Your Neck/CD |Live |
| Ozzy Osbourne & Miss Piggy | Born To Be Wild | Steppenwolf | Kermit Unpigged/CD |
| Ozzy Osbourne | Purple Haze | Jimi Hendrix | Stairway To Heaven, Highway To Hell/CCD |
| Ozzy Osbourne | Stayin' Alive | BeeGees |