M.O.A.B. is a stoner and sludge metal band from Turin, Italy, formed in 2018. They deliver crushing stoner-sludge from the Piedmont capital.

Machete is a hardcore/doom/sludge metal band from Essen, Germany, formed in 2025. Their sound fuses the confrontational energy of hardcore with the crushing weight of doom and sludge metal, representing the heaviest end of Essen's underground scene.

Machiavellian is a death metal and deathcore band from Skelmersdale, England, formed in 2019, incorporating sludge metal influences. They deliver crushing extreme metal built on devastating heaviness.

Mad Act is a progressive stoner and sludge metal band from Amiens, France, formed in 2019. They blend progressive ambition with stoner-sludge metal's crushing, groove-laden heaviness.

Magec is a doom and sludge metal band from Santa Cruz de Tenerife in the Canary Islands, formed in 2017. Their albums Departure Island and Ethereal Link deliver crushing sludge-doom from the volcanic archipelago off the African coast.

Magnetic TarTrap is a death'n'roll sludge metal band from Moscow, Russia, formed in 2009. Their 2023 album 'Overstoned' compiles ten tracks recorded in 2013 at Destroy the Humanity studios, blending heavy sludge with psychedelic stoner rock, punk, and death metal through a decade of creative output.

Magnitudo is a sludge and post-metal band from Bergamo, Italy, formed in 2016. They blend crushing sludge with post-metal's atmospheric dynamics from Lombardy.

Mahakala is a band from Athens, Greece, formed in 2020, having evolved from sludge and doom metal into heavy metal. Named after the Buddhist protector deity, their creative evolution reflects a journey from crushing heaviness to classic metal power.

Mahoney is an atmospheric sludge metal and metalcore band from Nakkila, Finland, formed in 2016. They blend atmospheric sludge's expansive textures with metalcore's aggressive dynamics.