M67 is a groove metal and hardcore band from Manaus, Amazonas, Brazil, founded in 2017 by Naveca Ogro and Gabriel Alladoh and named after the M67 fragmentation grenade. The band draws on Amazonian folklore for lyrical content, explored in their EP "Agouros Amazônicos," which features tracks themed around legends of the Brazilian Amazon including the single "Mapinguari Algoz" (2020).

Mamut is a Buenos Aires thrash and groove metal band featuring vocalist Theo Peltzer, guitarist Facundo Robles, and bassist Gerardo Cei, known for fusing classic and modern metal with Latin American folk rhythms. The band recorded their 2023 album 3 — an eight-track release — at Romaphonic Studios in Buenos Aires in December 2022.

Formed as a supergroup drawing from well-known names in the national underground, Marabô features vocalist Felipe Chehuan (formerly of Confronto and Cabeçudos), guitarist Davi Baeta, bassist Paulinho Coruja, and drummer Henrique Pucci. The band channels heavy groove and metalcore through dense riffs and politically charged lyrics, as heard on the single "Estacas," which was recorded, mixed, and mastered by Baeta and Pucci themselves.

Mate Cosido was a groove metal band from Buenos Aires, Argentina, whose lineup featured vocalist Lito Pared, guitarists Alejandro Venneri and Román Montesi, bassist Gerardo Lucero, and drummer Javier Dorado, who had previously played with Argentine metal legends A.N.I.M.A.L. The band released their self-titled album through EMI in 1996, recorded in June and July of that year and produced alongside Augusto Milharcic. The 12-track record remains their only known release before the band split up.

Mawiza is a Mapuche metal band from Wallmapu, Chile, formed in 2021 as the successor to Nunca Seremos Dichosos—a project that won the Pulsar Award (Chilean Grammy) for Best Metal Artist in 2020 for the album Kollong (2019). Performing in Mapuzungun, their ancestral language, and integrating traditional Mapuche instruments and rhythms into groove metal and metalcore, Mawiza have drawn international attention from acts including Slipknot and Gojira, the latter's Joe Duplantier appearing on their debut album ÜL (2025) on Season of Mist. Their work is as much a statement of Indigenous cultural preservation as it is a metal record.

Mercy Shot blend heavy and groove metal with hard rock influences into a muscular, hook-driven sound. Their 2022 album 'Brace for Impact!' showcases the band's range across ten tracks — from the churning 'Sink and Thrive' to the anthemic 'Massive Heart' — cementing their place in São Paulo's modern heavy rock scene.

Formed in Santos with a founding lineup of Marcus Vinicius on vocals, Fausto Pietro on drums, and Vinicius Guedes on guitar, Metallstein draw on old-school death metal, speed/thrash, and grindcore for a raw and uncompromising sound. The band released their self-titled debut single containing six tracks in early 2023 and have since appeared on the 'Workingclass In Roll – Brazilian Compilation' with the track 'Sonho Súbito'.

Metralleta is a heavy/groove metal band from Larroque, Entre Ríos, a small city in eastern Argentina seldom represented in the local metal scene. Their recorded output includes the 2009 album Todo o Nada and the follow-up Puente, released on August 1, 2014, which features tracks such as "Cuando los muertos viven," "Vértigo," and "Victoria."

Metralleta is a heavy/groove metal band from Larroque, Entre Ríos, a small city in eastern Argentina seldom represented in the local metal scene. Their recorded output includes the 2009 album Todo o Nada and the follow-up Puente, released on August 1, 2014, which features tracks such as "Cuando los muertos viven," "Vértigo," and "Victoria."