Mortticia is one of the leading NWOTHM acts to emerge from the south, blending classic 1980s heavy metal architecture with progressive and power metal sensibilities, drawing comparisons to Queensrÿche and Angra. The band released their debut EP "A Light in the Black" in 2020 — later issued on CD by Pest Records — and made a notable live statement when they opened for Angra in Porto Alegre in 2022.

Mortuario is a thrash metal band from Santa Cruz de la Sierra, Bolivia, active since 2004 under the Under Records label. The band built its catalog through a series of demos in the 2000s and early 2010s before releasing their debut full-length, Devastación, in 2025. Their sound draws on old-school thrash traditions with lyrical themes of death, destruction, and metal itself.

Mortuary was a death metal band from Buenos Aires, Argentina that was active from 2021 until their split-up. The band contributed the track "Addiction to Horror" to the South American death metal compilation Preservation of Death Vol. 2: South American Massacre — First Blood, their most documented public release.

Mortumbra is a four-piece black metal band from Osorno in southern Chile, describing themselves as "bards and minstrels devoted to dark and forgotten arts." They released their debut recording, PROMO MMXXV, in February 2025.

Mortuo is a one-man black metal project from Curitiba helmed by Vox Morbidus, who also operates several other underground solo ventures. The project draws on second and third wave black metal traditions, blending high-pitched vocals with keyboard textures over mid-to-fast tempos, and released the album "Old Memories of the Past" through Tornhate Records.

Mortuorum was a raw black metal band from Mauá that operated with an uncompromising anti-religious stance and a prolific underground output. The project released a string of short, aggressive recordings including "Marked for Death" (2021) and "Mortuorum III" (2022) before going silent.

Mortuário A.D. channels the raw, bestial energy of early Brazilian extreme metal through a death/thrash lens, citing Sepultura, Sarcófago, Mutilator, Vulcano, Obituary, and Hellhammer as touchstones. Their second release, "Die in Pain," dropped on Halloween 2024 and captures the horror-soaked ferocity the band has built its identity around.

Mortífera from Campina Grande holds a notable place in Brazilian metal history as one of the country's earliest all-female death metal bands, active from the late 1980s into the early 1990s and documented on Metal Archives with a 1989 rehearsal demo. Their brief existence in the northeast underground left a mark as a rare example of women fronting the uncompromising heaviness of early death metal in Brazil.

Mothercow plays a swaggering mix of southern rock grit and groove metal heaviness, channeling the spirit of Pantera and Down into a distinctly interior São Paulo setting. After a long hiatus, the band returned with their full-length debut "Death Before Defeat" in 2022, followed by the six-track EP "Baptized in Gasoline" in 2024.