Jazzcore is a punk jazz subgenre that incorporates elements of hardcore punk and heavy metal music alongside typical jazz instrumentation and improvisation. It is related to mathcore, cabaretcore and jazz metal.

John Zorn began to make note of the emphasis on speed and dissonance that was becoming prevalent in punk rock and incorporated this into free jazz. This began in 1986 with the album Spy vs. Spy, a collection of Ornette Coleman tunes done in the contemporary thrashcore style. The same year, Sonny Sharrock, Peter Brötzmann, Bill Laswell, and Ronald Shannon Jackson recorded the first album under the name Last Exit, a similarly aggressive blend of thrash and free jazz.

These developments are the origins of jazzcore, the fusion of free jazz with hardcore punk. Groups like Nomeansno , Victims Family , Massacre, and Naked City laid the foundations for what would later be described as math rock.