Los Angeles grindcore band Terrorizer formed in 1986 around vocalist Oscar Garcia, guitarist Jesse Pintado, and drummer Pete Sandoval, recording their sole classic lineup album World Downfall in 1989 for Earache Records with Morbid Angel's David Vincent producing and playing bass. The album has since been recognized as a foundational text of grindcore, and the band briefly dissolved after Pintado joined Napalm Death and Sandoval returned to Morbid Angel. A reformed lineup released Darker Days Ahead in 2006, though the original lineup never reconvened.

Los Angeles's The Dolemite Project have been colliding grindcore velocity with crossover thrash's d-beat swagger and classic thrash riffing since 2016, producing short, punishing songs designed to leave listeners winded. Named with an eye toward exploitation cinema, they bring the same irreverent aggression to their music — fast, noisy, and absolutely ferocious. In LA's vast and competitive underground, they've carved out a distinctive niche at the chaos end of the thrash spectrum.

Thieves is a California grindcore and crust punk act formed in 2013, channeling the raw, politically charged fury of crust into a grindcore format that is brief, loud, and absolutely unsparing. Operating without a fixed city listing, they embody the nomadic, anti-establishment spirit of the crust underground.

Los Altos, California's Thy Virtual Machine combine death metal's brutality with grindcore's blazing tempo and compressed fury, taking their conceptually unusual name from computing infrastructure and applying it to some of the most extreme sounds the genre intersection can produce. Formed in 2020 in the heart of Silicon Valley, they're a wry intrusion of tech-culture nomenclature into the underground.

Out of the small coastal enclave of Baywood-Los Osos, California, Toxic Wizard collapse genre walls with reckless abandon, fusing sludge heaviness, grindcore violence, power metal theatrics, and experimental noise into a deliberately unclassifiable whole since 2016.

Tripas Sangrientas is a goregrind band from West Covina, California, formed in 2023, dealing in the visceral, low-tuned carnage of gore-obsessed grindcore.

Twenty Twelve is a death metal and grindcore band from Ontario, California, formed in 2001, delivering compact bursts of extreme aggression within the death-grind tradition of the Southern California underground.