Magna Corporea is an Argentine one-man atmospheric and raw black metal project that released its debut album "Bliss of Non-Temporal Condition" in January 2023 on Regimental Records, followed by "Dialect of the Unborn (Birth Wound and Xenoglossia)" in November 2023. The project is available on Bandcamp and has also been distributed physically through Sunshine Ward Recordings.

Magna Umbra was a symphonic metal band from Blumenau, Santa Catarina, Brazil, active from 2009 until disbanding in 2017. The band released the full-length album Someone at Your Door in 2015, a ten-track record showcasing their orchestral and melodic approach to heavy metal.

Magnalucius is one of Chile's longest-running power metal bands, formed in Concepción in 2000 and considered a pioneer of the genre in the country. They released their debut album The Quest... in 2002, opened for Stratovarius in Santiago in 2003, and remain active — most recently serving as the opening act for Sonata Arctica in Concepción in April 2025.

Magnolia's Devil is a stoner metal and rock band from Petrópolis, Rio de Janeiro, Brazil, formed in 2014. The band released the EP Dom Pedro on Trumpet in July 2014, a five-track record described as fuzzy, blues-based heavy rock drawing comparisons to a Sabbathian psychedelic sound.

Magzilla was a doom, stoner, and sludge metal band from São Paulo, Brazil, active from 2013 until splitting up in 2017. The quartet — featuring Guilherme Foresti on vocals and guitar, Pedro Alves on guitar, Joe Borges on bass, and Leandro Furini on drums — released two records: The Oath in March 2016 and a self-titled album in July 2017.

Mahanvhantara was a black metal band from Aracaju, Sergipe, Brazil, formed in 2007 with lyrical themes rooted in Thelema, Ophiolatry, and Gnostic Luciferianism. The band released the demo O Decantar dos Dragões Decaídos in July 2007, recorded at Cathal Dallan Home Studio in Aracaju, and later returned with the album Dissolutionem - Finis Coronat Opus in September 2018, released through Black Hearts Records.

Makabro is a heavy/thrash/power metal band from Villa Regina, Río Negro, formed in 2014 and active in Argentina's Patagonian underground scene. The band self-released a six-track studio EP in 2022, available on Spotify as "Full EP Estudio 2022", documenting their progressive thrash sound.

Maktub is a Brutal Death Metal and Grindcore band from Monterrey, Nuevo León, Mexico, formed in 2025 and signed to SBDC Records. The band released their self-titled debut EP in August 2025, a nine-track record distributed digitally through Bandcamp.

Malacara is a veteran Buenos Aires heavy metal band with two albums listed on the Metal Archives: "Vuelvo a tu camino" and "Mi rebelión". The band appeared on the 2006 Argentine tribute compilation "El Barón Vuela Sobre Argentina — Tributo a Barón Rojo", contributing a cover alongside bands such as Riff and Lethal.