Madhouse is a thrash metal band from Rancagua, in Chile's O'Higgins Region, formed in 2019. The band operates independently within the active Chilean thrash metal underground, drawing on the aggressive traditions of the genre.

Madkill is an old-school thrash metal band from São Paulo, Brazil, formed in 2014 and rooted in the aggressive speed and thrash traditions of the Brazilian scene. The band released their debut album "Mass Destruction" in 2014 and followed it with "Intense Violence" in 2019, a ten-track record described as old school thrash/speed metal with tracks such as "Thrash City" and "Saint Death". They have remained active into the mid-2020s, releasing the politically charged "Protesto" in 2024.

Maelström is a progressive gothic metal band originally from Rio de Janeiro, Brazil, formed in 1994 and one of the longer-running acts in the country's gothic metal underground. The band released a self-titled debut album in 2001 and a second full-length, "Decline of the West", in 2006 through Force Majeure Records, which also issued a special double-CD edition bundling both releases. Guitarist, keyboardist, and vocalist Alexandre Cegalla has been a central figure in the band throughout its existence.

Maerebat is a Buenos Aires black metal act featuring Lord Abductum on music and Satani Lamentatio on lyrics, with drums handled by Favio Guzman. The band released their debut four-track recording "Amos del Caos" in April 2024, having tracked it the previous year before editing and releasing it independently.

Maestrick is a progressive power metal band from São José do Rio Preto, São Paulo, Brazil, formed in 2011 around a sound that blends power metal with progressive rock, world music, and theatrical, multimedia influences. Their debut album "Unpuzzle!" (2013) established their conceptual approach, drawing on surrealism and the arts, while the two-part "Espresso della vita" series — "Solare" (2018) and "Lunare" — forms an ambitious concept album spanning the 24 hours of a day. The band's work has been released in Brazil, Germany, and Japan, with the current lineup featuring vocalist Fábio Caldeira, guitarist Guilherme Henrique, bassist Renato Somera, and drummer Heitor Matos.

Magiak is a black metal band from Bogotá, Colombia, formed in 2026. The band released their debut demo "Tempus Fugit" in January 2026, a six-track recording featuring Spanish-language song titles rooted in themes of horror and darkness.

Magicus Pacha Moon is a Death/Doom Metal band from San Gabriel, Carchi, Ecuador, originally formed in 2001 and revived in 2019. Their 2021 debut album "Vientos de Immortalidad" draws on old-school death/doom influences, exploring themes of nature, solitude, and introspection through ten tracks recorded under the cold shadow of the Andean mountains. The band is currently active and releases through Wolfgang Records.

Magika is a Buenos Aires melodic heavy metal band that released two albums through their early years: "La Fuerza Que Nace" (2004), recorded at Black Magic Studios and featuring guest vocals from Adrián Barilari of Rata Blanca, and "Lejos de Dios" (2005), also recorded at Black Magic Studios. "La Fuerza Que Nace" was recognised as one of the five best albums of 2004 on Buenos Aires radio program Tiempos Violentos on FM Rock & Pop.

Magister is a melodic progressive metal band from São Paulo, Brazil, rooted in European heavy metal influences blended with early music elements and 1970s progressive rock. The band released their self-titled debut album in 2000 and a follow-up MCD, In the Kingdom of the Blind, in 2001, with a third album, The Art of Changes — originally recorded in 2002 at Creative Studios in São Paulo — eventually seeing official release in 2017. Their lineup has included André Evaristo on vocals and guitar alongside Fabio Gusmão on guitar, Robson Hammer on drums, and JC Alencar on bass and vocals.