Arandu Arakuaa is a folk metal band from Brasília, Brazil, founded by guitarist Zândhio Aquino, who began composing songs in Old Tupi around 2008 and released the band's first EP in 2012. Their name means "knowledge of the sky cycles" in Tupi-Guarani, and their music fuses heavy metal with Brazilian indigenous traditions, incorporating the languages and musical styles of the Tupi, Xerente, and Xavante peoples. Their discography includes the albums Kó Yby Oré (2013), Wdê Nnãkrda (2015), Mrã Waze (2018), and Ainãka (2022).

Arbach was a black metal band from Anápolis, Goiás, Brazil, founded by Emperor Diavolos with the stated aim of combining melody and aggression in the tradition of classic Scandinavian black metal. The band released the demo The Warriors of Pagan Empire (2007), a full-length titled Left Hand Path (2015), and the album Bellum Aeterna (2018) before splitting up.

Arcaico formed in Avellaneda in the greater Buenos Aires area with a lineup of Adrián Saladino on vocals, Miguel Bustos and Demian Yanelli on guitars, Nico Meire on bass, and Federico Gusso on drums. The band released their self-titled EP in February 2013 through Black Eclosion Digital Record Label, a four-track effort that included the tracks "Tu Cabeza Es Mi Bandera" and "Revolución". Their sound blended melodic death metal riffing with aggressive rhythms rooted in the Argentine extreme metal underground.

Arcana Elysium is a female-fronted symphonic metal band from Petrópolis, Rio de Janeiro, Brazil, formed in 2019. Their debut album Corpus Callosum, released in May 2021, showcases a heavier-than-typical symphonic sound that at times veers toward symphonic death metal territory.

Arcane Sanctuary is a symphonic progressive metal band from Rosario, Argentina, built around guitarist and bandleader Francisco Romero alongside vocalist Juliana Penacino, bassist Luciano Vittone, and drummer Jeremías Scoccimarro. The band released their debut full-length album "The Traveler's Diary" in August 2025, a nine-track record described as a journey through human emotions, time, life, and death. Their music fuses the complexity of progressive metal with orchestral and symphonic arrangements, making them one of Argentina's emerging acts in the genre.

Arcanen (originally active as Arkanen from 2003 to 2009) was a melodic death metal band from Antofagasta, Chile. The five-piece lineup featured Gonzalo Jara on vocals, César Aranda on bass, Eduardo Cuadra on guitar, Javier López on guitar and vocals, and Víctor Gutiérrez on drums. The band released the six-track EP Points of Projection in 2006, drawing comparisons to Swedish melodic death metal acts such as Dark Tranquillity and At the Gates.

Arcania is an epic and atmospheric black metal band from Poços de Caldas, Minas Gerais, Brazil, formed in 2013. The band draws on themes of fantasy, nature, and landscapes, and released the album A World Forsaken in 2023 under the Bandcamp handle arcaniaepicbm.

Arcanjo is a Christian thrash metal band from Brasília, Distrito Federal, Brazil, with origins tracing back to 1994. The band's lyrical themes center on Christianity, perseverance, and redemption, and they released a split with Soul Factor in 2001 before a period of inactivity and subsequent reformation.

Architeuthis Dux is a death-grind band from Mar del Plata, Argentina, featuring Chela on vocals, Blass on guitar, Pitu on bass, and Joaco on drums. The band has built an extensive catalog of recordings, including releases such as "Apotheosis of the Guillotine", "Acropolis", "Hecatomb", and a split with Indonesian band Jeritan. Named after the scientific designation for the giant squid, they are one of the most prolific acts in the Argentine extreme metal underground.