Crust punk (often simply crust) is a form of music influenced by anarcho-punk, hardcore punk and extreme metal. The style, which evolved in the mid-1980s in England, often has songs with dark and pessimistic lyrics that linger on political and social ills. The term "crust" was coined by Hellbastard on their 1986 Ripper Crust demo.

Crust is partly defined by its "bassy" and "dirty" sound. It is often played at a fast tempo with occasional slow sections. Vocals are usually guttural and may be growled or screamed. Crust punk takes cues from the anarcho-punk of Crass and Discharge and the extreme metal of bands like Venom and Celtic Frost. While the term was first associated with Hellbastard, Amebix have been described as the originators of the style.

Crust punk is a derivative form of hardcore punk and anarcho-punk, mixed with metal riffs. The tempos are often fast, but just short of thrashcore or grindcore, though many groups confine themselves to a crawling, sludgy pace. The overall musical sound has been described as being "stripped down". Drumming is typically done at high speed, with D-beats sometimes being used.