Heterodoxa is a thrash/death metal and crossover band from Junín de los Andes, Neuquén, formed in 2015 by members known as Mati, Bruno, Jano, and Tincho. The band released a self-titled debut in February 2015 and followed it with the EP "La Tierra Esta en Crisis" in April 2019, both independently released.

Heulend Horn is a one-man epic Viking/black metal project from Buenos Aires, with all instruments performed and composed by Friedrich Curwenius since 2003. The project's discography includes the debut "The Saga of the Draugr" (2003), the concept album "From the Caucasus to Gotland" (2006) released via Furias Records, and "Fragments from the 13th Century" (2013), all drawing on Viking mythology and medieval history.

Hevilan is a heavy/symphonic metal band from São Paulo, Brazil, founded by guitarist Johnny Moraes. Their debut album The End of Time was released in 2013 in Brazil and Japan, and later picked up by Massacre Records for a European release in 2015, earning the band spots opening for Masterplan and Edu Falaschi. A second full-length, Symphony of Good and Evil, followed in 2021.

Hevnoraak is a Brazilian doom/death metal project formed in 2019. Their debut release Sinking Into Nothingness, issued on February 8, 2019, comprises three tracks — "Tangible Existence," "A Fair Death," and "Ensnared Aura (An Ode to Emptiness)" — establishing a slow, oppressive sound rooted in atmosphere and weight. A cassette edition of the release was pressed by Final Hours of Christ Productions in 2022.

Hexen Sabbat is a dark doom metal band from Rio de Janeiro, Brazil, formed in 2024. The band released their debut album Dramatic Dreams on April 11, 2024, through Eclipsys Lunarys Productions, recorded at HR Studio and Pré-Sound Studio with production by Orion Gobath and David Malkuth. Their sound blends slow, heavy doom textures with occult and melancholic themes.

Hexenshade is a solo black metal and dungeon synth project from Santa Fe, Argentina, founded in 2024 by the artist known as Woryon. The debut album "The Revelation of Doom..." was recorded in January 2025 in Santa Fe and released as a limited cassette by Dutch label Wolfkult Religion, drawing heavily on early Bathory in its raw, occult approach.

Hibria is a power/speed metal band from Porto Alegre, Rio Grande do Sul, Brazil, formed in 1996 and internationally recognized for their technical precision and ferocious tempo. Their debut album Defying the Rules (2004), mixed by Piet Sielck of Iron Savior, was released in Japan where it found a devoted following, and the band went on to support acts including Metallica and Black Sabbath. Subsequent albums include The Skull Collectors (2008), Blind Ride (2011), Silent Revenge (2013), and the self-titled Hibria (2015).

Hicsos is a thrash metal band from Rio de Janeiro, Brazil, founded in 1990 and one of the city's longest-running acts in the underground scene. Their sound fuses thrash with hardcore, addressing themes of religion, politics, and social conflict, and they have documented their run with albums including Eatin' Concrete (2004), Technologic Pain (2007), and Circle of Violence (2011), the last of which was re-released in 2018 with a DVD documentary titled 26 Years of Thrash Violence. The band is signed to Metal Blast Records and remains active.

Hidrommel is a heavy metal band from Lavras, Brazil, formed in 2022. The band released their debut album We Are the Seas in 2024, a ten-track record that draws on classic heavy metal traditions with a seafaring lyrical theme spanning tracks such as "Pirates of 21st Century," "Sirena's Call," and "Natural Born Drinkers."