D.O.A. is a Canadian punk rock band from Vancouver. They are often referred to as being among the "founders" of hardcore punk, along with Black Flag, Dead Kennedys, Bad Brains, Angry Samoans, Germs, and Middle Class. Their second album Hardcore '81 was thought by many to have been the first actual reference to the second wave of the American punk sound as hardcore.

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".