Organismos - Manejos Invisibles
n, 2011, Me Saco un Ojo Records UK
Ordo Inferus - Invictus et Aeternus
n, 2014, Doomentia CZ
Orden Ogan - Final Days
ss, 2020, AFM D - clear vinyl
Orcrist - Fallen
n, 2011, Aphelion UK
Oppressor - The Demos
n, 1993, Hammerheart NL (2024) blue vinyl
Onslaught - Power from Hell
ss, 1985, High Roller D (2013)
Omega Infinity - Solar Spectre
n, 2020, Seasons of Mist FRA
Olde - The Gates of Dawn
n, 2013, Soulseller NL
Old Mans Child - Vermin
n, 2005, Cosmic Key NL (2024)
Old Mans Child - Revelation 666: The Curse of Damnation
n, 2000, Cosmic Key NL (2024)
Old Mans Child - In Defiance of Existence
ss, 2003, Abstract Emotions SPA (2024)
Old Mans Child - Ill-Natured Spiritual Dimension
n, 1998, Cosmic Key NL (2025)
October Tide - In Splender Below
n, 2019, Agonia PL
Obtest - Auka Seniems Dievams
n, 2001, Leda Takas LIT (2011)
Obtest - Amžina Aušra
n, 2011, Ledo Takas LIT
Obsidian Kingdom - A Year with no Summer
n, 2016, Season of Mist FRA
Obsession - Scared for Life
ss, 1986, High Roller D (2024)
Obsession - Order of Chaos
ss, 2012, High Roller D (2024)