Kaatayra is the one-man atmospheric folk black metal project of Brasília-based musician Caio Lemos, launched in 2019. Lemos weaves traditional Brazilian folk instrumentation and regional mythology into raw black metal frameworks, drawing its name from a word meaning "Son or Daughter of The Woods." The project proved immediately prolific, releasing two full-lengths in its debut year — No Ruidar da Mata que Mirra and Nascido Sob o Signo Incivilizatório — and followed with further albums including Só Quem Viu o Relâmpago à Sua Direita Sabe (2020) and Inpariquipê (2021).

Kadabra is a heavy metal power trio from Vinhedo, São Paulo, Brazil, whose sound blends traditional heavy metal with Bay Area thrash influences and elements of Brazilian death metal. The band debuted with Devastation's Songs (2017) and followed with Remains of the Past (2019) before releasing Underground Resistance (2021), their first album recorded entirely in Portuguese.

Kadavro is a death/thrash metal band from Neuquén, Argentina, whose members perform under pseudonyms El Cadaver, G.G, Machacador, and Weedfinder. They released two records in 2021 — Evil Entities from the Hidden Past through Evil Damnations Records, and Paladar Negro — before following up with Procession of Evil in 2024.

Kaer Morhen is a melodic death metal band from Buenos Aires, Argentina, formed in 2017 by guitarists Andres and Adrian Ojeda alongside vocalist Christopher Amato, bassist Ariel Pirelli, and drummer Adrian Ojeda. They debuted with a self-titled EP in 2017 and followed with the three-track release Tales Deserve to Be Told in September 2018.

Kafziel is the solo instrumental progressive metal project of guitarist Pablo Cubilla from San Nicolás de los Arroyos, Argentina, who launched it in 2013. Cubilla, also a member of Rebhellion and Hatred Source, has maintained a prolific output across more than a dozen releases, including Defying Gravity (2015), Elements (2019), Ephemeral (2020), and Rewired (2024).

Kaiten is a thrash/death metal band from Valinhos, São Paulo, Brazil, formed in 2010. The band released the album Crash and Burn, operating as an unsigned independent act within the São Paulo underground metal scene.

Kala Sumeriah is a stoner/groove metal band from Mendoza, Argentina, featuring vocalist Gus Banco Pravata, guitarist Edu Palladino, bassist Martin Fumarola, and drummer Alvaro Garcia Bensi. Their fourth studio album, Wormoboros, was released on April 27, 2022, produced by the band and recorded at The Arrival Studio.

Kalte Seetürme is a black metal and ambient project from São Paulo, Brazil, formed in 2024. The project has released three recordings — Kristallhallen, Nachtweg, and Blasser Glanz — all available on Bandcamp, with German-language titles pointing toward a Nordic-influenced aesthetic within the Brazilian underground scene.

Kalvarius is a melodic and progressive heavy metal band from Manaus, Amazonas, featuring vocalist Mardson Campell, guitarist James Oliveira, drummer Renato Melo, keyboardist Jackes David, and bassist Mykon. The band built a following in the Amazon region and beyond with their debut EP Visão do Rei and were selected for the Oxigênio Compilation among the fifteen greatest independent bands in Brazil. The group's lyrical themes drew from evangelical Christian values, channeling messages of peace and hope through a virtuosic prog metal sound.