New York hardcore is both the hardcore punk music created in New York City and the subculture and lifestyle associated with that music. New York hardcore grew out of the hardcore scene established in Washington, D.C., by bands such as Bad Brains and Minor Threat. Initially a local phenomenon of the 1980s and 1990s, New York hardcore eventually grew to establish an international reputation with little to moderate mainstream popularity but with a dedicated and enthusiastic underground following, primarily in Europe and the United States. With a history spanning over more than four decades, many of the early New York hardcore bands are still in activity to this day. Some of them have been continuously or almost continuously active since their formation as well as having reunion shows.

Hardcore punk is a punk rock music genre and subculture that originated in the late 1970s. It is generally faster, harder, and more aggressive than other forms of punk rock. Its roots can be traced to earlier punk scenes in San Francisco and Southern California which arose as a reaction against the still predominant hippie cultural climate of the time. It was also inspired by Washington, D.C., and New York punk rock and early proto-punk. Hardcore punk generally disavows commercialism, the established music industry and "anything similar to the characteristics of mainstream rock" and often addresses social and political topics with "confrontational, politically charged lyrics".