Frozen Tears were a gothic/doom metal band from Valdivia, Chile, formed in late 2001 with a lineup that included violin alongside guitar, bass, and drums. The band released two demos — "Winds of Sadness and Darkness" (2002) and "Midnight Mists" (2003) — before going inactive.

Frummyrkrið is a progressive black and viking metal band from Brazil, formed in 2021 as a trio of three siblings. Their debut album Dauðans Myrkri (2021) — the title meaning "The Darkness of Death" in Icelandic, mirroring the band's Icelandic-derived name meaning "Primordial Darkness" — weaves together progressive rock, ambient textures, and viking metal in the vein of Enslaved, earning a 91/100 score from The Elite Extremophile.

Frustrated Existence is a death/thrash metal solo project from Poço Fundo, Minas Gerais, Brazil, driven by multi-instrumentalist Ruben Alvim, who handles guitars, bass, and vocals. The project released its self-titled debut album in July 2023, a 11-track record recorded between November 2021 and February 2022 in a home studio, with tracks including "Shortcuts to Slavery" and "Implode this Damned System."

Fuck the Law is a doom/death/stoner metal band from Rio de Janeiro, Brazil, formed in 2014. Citing Black Sabbath, Celtic Frost, Cathedral, Entombed, and Napalm Death as primary influences, the band crafts a heavy, riff-driven sound that blends traditional doom with death metal weight.

Fuego Interior is a deathcore and metalcore band from Buenos Aires, Argentina, who released their debut full-length "El Camino Más Difícil" in 2013, a nine-track album running roughly 34 minutes. Over a decade later they returned with their second album "Los Límites de la Realidad" (2024), incorporating djent elements and dense breakdowns alongside their established groove.

Fuego Negro are a black metal/punk band from Valparaíso, Chile, formed in 2013 and active on the Diskordia Records label. Their music sits in the raw, confrontational intersection of black metal aesthetics and punk aggression that has characterized a distinct strain of the Chilean underground scene.

Fuentealba is a Buenos Aires stoner/doom trio consisting of Mario Banega on guitar and vocals, Federico Pelfini on drums, and Gonzalo Vazquez Ubiedo on bass. The band released their debut EP "Presente" in December 2019, followed by "Fuentealba Km 0" (2022) and the three-track release "Mazmorras" in November 2024.

Fuenteovejuna was a Buenos Aires groove/death metal band that released a self-titled four-track album on July 9, 2018. The band blended groove metal and death metal with elements of thrash, and split up after a short run.

Fuerza Oculta (released under the name Fuerzas Ocultas on Bandcamp) was a heavy metal band from Rafaela, Argentina, who released a self-titled album on August 1, 2018. The band has since split up, leaving behind this sole recorded output from their brief existence.