Maimed is a sludge and doom metal act from the seaside city of Brighton, layering crushing heaviness over crawling tempos since 2021. The band channels the murky underside of the English south coast into oppressive, slow-burning compositions.

Malasangre is a sludge, drone, and funeral doom metal band from Voghera, Italy, formed in 2019. Their Italian name meaning "bad blood" captures the suffocating heaviness of their drone-doom.

MallevM is a sludge/doom metal quartet from Slavonice, Czech Republic, whose 2023 "rehearsal dungeon demo" captures five extended compositions of crushing, atmospheric heaviness. Their sound emphasizes slow-burning instrumental passages and throat-shredding vocals in the tradition of the genre's most oppressive practitioners.

Malämmar is an atmospheric sludge, doom, and post-metal trio from Barcelona, Spain, formed in 2016. Their releases including the Vendetta LP and performances at dunk!festival deliver crushing atmospheric heaviness that defies easy categorization.

Manaja is a sludge and stoner metal band from Tampere, Finland, formed in 2023. They channel crushing sludge and stoner metal from Finland's industrial heartland.

Mang Ont is a stoner, sludge, and doom metal band from Tartu, Estonia, formed in 2012, blending heavy, slow riffs with psychedelic drone and noise. Their Estonian-language releases including Külmavärinad and Sügavkülmunud tuum channel crushing sonic weight through modular synth, bass, and guitar.

Mantar is a two-piece sludge/black metal juggernaut from Bremen, Germany, achieving massive heaviness with only drums and guitar across a prolific discography from "Death By Burning" (2014) through "Post Apocalyptic Depression" (2025). Their sound combines flogging beats, blackened melodies, and doom mayhem, drawing from Melvins, Motörhead, and Darkthrone without a bass guitar in sight.

Marasme is an experimental sludge metal band from Mallorca, Spain, active since 2008, delivering darkness, rage, and hopelessness across seven releases. Their genre-defying sound is too blast-beat heavy for post-metal, too melodic for sludge, and too primitive for post-black, culminating in 2025's Fel dedicated to a fallen bandmate.

Marazm is a sludge/groove metal act from Olsztyn in Warmia-Masuria, active since 2019. The band channels the stagnation suggested by their name into crushing, slow-moving heaviness.