MotherSloth is a stoner, doom, and sludge metal band from Madrid, Spain, formed in 2008. Their extensive catalog spans releases from Moribund Star to Death Flower, delivering crushing doom-sludge with stoner metal's hazy grooves.

Mothertrucker is a stoner, sludge, and doom metal band from Birmingham, England, active since 2004. With two decades of activity, they deliver crushing stoner-sludge-doom from the West Midlands.

A three-piece instrumental stoner doom band from the port city of Oudenburg in West Flanders, Belgium, active since 2012 on Polderrecords. Their self-titled debut EP (2014) established their instrumental 'polder rock' identity — a slow, crushing blend of stoner riffs, sludge, and old-school hard rock — and their concept album 'Oumuamua' extended that approach into heavier post-metal territory.

Mouflon is a doom/death metal band from Arnhem, the Netherlands, formed in 2018. They craft crushing doom-death compositions steeped in oppressive heaviness.

Mould is a sludge/doom metal band from Terneuzen, the Netherlands, formed in 2020. They channel crushing sludge-doom through abrasive riffs and oppressive weight.

A psychedelic doom metal act from Wrocław, Mountain of Misery has been crafting heavy, mind-expanding compositions since 2023. The band channels the desolation of their name into crushing, hallucinatory doom.

Mourners is a funeral doom metal band from Timișoara, Romania, formed in 2017. They craft glacially paced funeral doom of devastating heaviness.

Mourning Dawn is a black and doom metal band from Paris, France, active since 2003. With over two decades of activity, they deliver crushing black-doom from the French capital.

Mourning Mist is a avant-garde black metal (early); doom metal (later) band from Perugia, Italy, formed in 2017. They fuse black metal's cold fury with doom's crushing weight.