Karyttah is a power metal band from São Paulo, Brazil, founded by guitarist and vocalist Fábio Lofts, whose debut album New Age – The Age of Karyttah (2017) blended classic power metal with melodic and symphonic influences drawn from Iron Maiden, Helloween, and Fates Warning. The band's name derives from the Latin caritas (charity), reflecting a commitment to positive, uplifting lyrical themes. Lofts handled virtually all instrumental duties on the debut before expanding the project into a full ensemble.

Karçaz is a solo black metal project from Belo Horizonte, Minas Gerais, created by Lucas Damaso under the pseudonym Profanus Damasus at the end of 2023. The name is derived from the Portuguese word "carcaça" (carcass), and the project spans black metal, black/death, and atmospheric styles across numerous self-released recordings including Hávamál, Aeternum Tormentum, and Codex Regius, all made available on streaming platforms in 2024.

Kasbeel is a black metal band from Temuco, Chile, signed to Australis Records, whose name is drawn from the fallen angel Kasbeel described in the Book of Enoch — the guardian who rebelled against God after witnessing his self-crowning. Their 2015 full-length Rebellion and Opposition, recorded at Acusti-k Studios in Temuco, delivers raw and violent black metal with satanic and anti-Christian themes, drawing comparisons to Darkthrone and Marduk.

Kassiuz is a heavy metal band from Pico Truncado, Santa Cruz, Argentina, widely regarded as one of the pioneering acts of Patagonian heavy metal. The band self-released their debut demo in 2014, featuring tracks including "El Judas," "Redencion," "Primitivo Tehuelche," and "Patagonia," all recorded and mixed in their hometown. Their 2018 album Amigo de Metal featured a guest appearance by Carlos Cabral of veteran Argentine metal band Tren Loco on the title track.

Kataphero is a melodic death metal band from Natal, Rio Grande do Norte, Brazil, active since 2009, whose sound blends doom and black metal atmospheres with somber, introspective melodies. Their discography spans four albums: Life (2012), From Dust (2015), Veil of Illusions (2022), and From the Science of the Black Earth (2025), showing sustained creative output over more than a decade. The band's current lineup centers on brothers Paulo Henrique Santiago (vocals, guitar) and João Felipe Santiago (bass), alongside guitarist David Cantidio and drummer Rafael Borges.

Katarock is a thrash/death metal band from Florencio Varela, Buenos Aires, Argentina, originally formed in 1993 and later resuming activity from 2016 onwards. Their early releases include a five-track demo from 1994 and the promo single "Mutilador" from 2001. The band contributed the track "Bailanteros Q.E.P.D." to the 1997 Argentine metal compilation Nuevos Guerreros Vol. 1 on Yugular Records.

Katarsis Tenebris was a raw black metal band from Ponta Grossa, Paraná, Brazil, active from 2017 until splitting up around 2020. The band released the demo Cursed Plains of Mortality in May 2018, followed by the three-track demo Black KVLT in March 2019, exploring themes of darkness, occultism, and depression. Both recordings were self-released as digital albums under the banner of Brazilian raw black metal.

Katastrofy is a death metal band from Anchieta, Espírito Santo, Brazil, formed in 2006 and operating independently throughout their career. The band contributed the track "Blasphemy Or Die By Lie" to the Fortaleza Metal Vol. IV compilation in 2008, marking their earliest documented recording. Their lyrical themes center on blasphemy, death, and anti-religious subjects.

Kathartica is a heavy and stoner metal band from Rio de Janeiro, Brazil, formed in 2022 by guitarist Gabriel Policarpo and bassist Matheus Motta, with drummer Yael Torres and vocalist Jessé Monteiro completing the lineup. Drawing from classic heavy metal and a wide range of influences, the band blends weight and groove into their metallic sound. They are active on Bandcamp and Spotify as an independent act.