Cyber Croatoan is an extreme industrial and gothic metal project from Goiânia, Goiás, Brazil, founded by vocalist and composer Phillipe Vitriol with the aim of blending extreme metal with electronic music. The band draws influences from Cradle of Filth, Rammstein, Hocico, and Psyclon Nine, combining guttural and operatic vocals over a backdrop that shifts between industrial gothic, djent, doom, and symphonic elements. Their debut album "Past of Pain" was released in 2013, followed by the EP "New Vision of Pain" in 2019.

Cygnus Rift is a heavy and gothic metal band from Rancagua, in Chile's O'Higgins region, with themes spanning death, power, and revenge. The band released a string of singles from 2022 onward, including 'In My Darkest Hours' and 'Brother's War', before issuing their debut full-length 'Arcane Heptagon Artificers' in 2026.

Cystus is a goregrind and death metal solo project from Cuiabá, Mato Grosso, Brazil, created by the musician known as Goreterrorist, who also performs in bands including Gorempire and Heretic Razor. The project debuted in August 2021 with the demo "Putrid, Fetid and Corrosive," recorded entirely by Goreterrorist at Grotesque Homestudios in Cuiabá, blending D-beat rhythms with gore-themed death metal and grindcore extremity.

Cárcere is a thrash metal band from Rio de Janeiro, Brazil, formed in 2018. The independent band released their debut EP "Crimes de Guerra" in December 2018, a five-track slab of aggressive Brazilian thrash rooted in the classic traditions of the genre.

Cão do Inferno de Quaresma was a short-lived raw black metal project from São Paulo, Brazil, active in 2022–2023 before splitting up. The project was led by Lady Svarta on vocals, with Mask of Darkness handling all instruments, and released a self-titled album in July 2022 as well as appearing on the Podreira Records "4 Way Split" compilation in December 2022.

Cérbero is a power/speed metal band from São Paulo, Brazil, listed on Metal Archives with an active status. The band plays fast, aggressive metal in the power and speed metal tradition and has released material available on Bandcamp. They share a name with a separate split-up thrash metal act from Recife, Pernambuco.

Cérebro de Galinha is a crossover/thrash hardcore band from Marabá, Pará, Brazil, formed around 2015 and operating independently. The band plays aggressive, politically charged material and has released two albums: "Sociedades Secretas" (2018) and "Norte em Chamas" (2021).

Céu em Chamas is a melodic death metal and metalcore band from Itapira, São Paulo, Brazil, formed in 2014. The band draws from a wide range of extreme music including punk, hardcore, grindcore, and thrash while maintaining a melodic core, and released their debut EP "Sopro da Destruição" in 2014 followed by the full-length "Infernal" in 2017, recorded at Black Stone Studio.

Círculo Polar is an Argentine black metal project that released the album Atemporal in 2015, establishing the band's raw and atmospheric approach to the genre. The project has maintained an underground presence through its Bandcamp page, where tracks such as Mar Muerto reflect a cold, minimalist black metal aesthetic.