Oak - Oak
n, 2009, A389 Recordings USA
Obituary - Dead
ss, 1998, Listenable FRA (2018)
Obsession - Order of Chaos
ss, 2012, High Roller D (2024)
Obsession - Scared for Life
ss, 1986, High Roller D (2024)
Obsidian Kingdom - A Year with no Summer
n, 2016, Season of Mist FRA
Obtest - Amžina Aušra
n, 2011, Ledo Takas LIT
Obtest - Auka Seniems Dievams
n, 2001, Leda Takas LIT (2011)
October Tide - In Splender Below
n, 2019, Agonia PL
Old Mans Child - Slaves of the World
n, 2009, Floga GRE (2018)
Olde - The Gates of Dawn
n, 2013, Soulseller NL
Omega Infinity - Solar Spectre
n, 2020, Seasons of Mist FRA
Omen - Battle Cry
ss, 1984, High Roller D (2022)
Omen - Into the Arena
n, 2012, No Remorse GRE
Omen - Teeth of the Hydra
n, 1989, Black Beard ITA (2021)
Oniricous - Ritos Diabolicos
n, 2013, Equinox SPA (2015)
Onslaught - The Force
ss, 1986, High Roller D (2019)
Oppressor - The Demos
n, 1993, Hammerheart NL (2024) blue vinyl
Opprobrium (Incubus) - Serpent Temptation
ss, 1988, High Roller D (2023)