Ab-Irato was a death metal band from Río Gallegos, Santa Cruz, one of the few extreme metal acts to emerge from Argentina's remote Patagonian south. The band contributed tracks including Adicto a la Ira, Gritos del Muerto, and Gangrena Cristiana to the regional compilations Memorias de Muerte IV (2005), Memorias de Muerte VII (2006), and Abismo Sureño (2007) before splitting up.

Abaddonsheol is a Venezuelan black metal project formed in 2023, exploring themes of depression, existentialism, occultism, and loneliness. The project released a pair of singles and the EP Andras in 2023, followed by the single Emissary for a Mind of Dead Memories in 2024.

Abadon is a black metal band from Curitiba, Paraná, formed in 1991 and one of the more enduring acts in Brazil's southern black metal underground. The band explores themes of Satanism and human misanthropy through a raw, orthodox black metal approach. After an extended hiatus they returned to activity in 2021 with a lineup including members operating under the pseudonyms Azrael, Void, and Perversor.

Abandono is a depressive black metal (DSBM) project from Santa Catarina, Brazil, formed in 2014. The band operates within Brazil's active DSBM underground, crafting minimalist, emotionally desolate black metal with an emphasis on atmosphere and introspection over technical aggression. Santa Catarina has produced a number of raw underground metal acts, and Abandono represents the state's contribution to the depressive black metal subgenre.

Abate is a pagan black metal band from São Francisco Xavier, a small mountainous district in the state of São Paulo, formed in 2013. Their music incorporates pagan and naturalistic themes typical of the subgenre, drawing on the forested, isolated character of their home region in the Serra da Mantiqueira highlands. They maintain a Bandcamp presence and remain active within Brazil's underground pagan metal scene.

Abatter is a heavy/thrash metal band from Florianópolis, Santa Catarina, formed in 2018 and currently on hold. The band plays a straightforward blend of old-school heavy metal and thrash, operating out of Florianópolis — a coastal city that has produced a modest underground metal scene largely overshadowed by larger Brazilian metal centers. Their Bandcamp page documents their recorded output before activity was suspended.

Abattoir is a Brazilian black metal act formed in 2020, representing the younger wave of the country's underground black metal scene. Emerging during a period of renewed interest in raw and orthodox black metal across South America, the band operates with a deliberately underground, self-released approach. Their Bandcamp presence serves as their primary distribution channel for demos and early recordings.

Abbathor is a Satanic black metal band from Concepción, Chile, formed in 2023. Their debut full-length, "From the Sight of Goat" (2025), spans ten tracks and 41 minutes of raw, orthodox black metal built around themes of Satanism and ancient paganism. The band made an early live appearance supporting Execrator in Concepción in February 2025.

Abducción is a death metal band from José C. Paz, Greater Buenos Aires, active in the Argentine brutal underground since 2013. The band contributed the track El rapto to the 2015 compilation Aquelarre - Misa uno, a multi-band release documenting the extreme metal underground across Argentina.