The 40th World Science Fiction Convention (Worldcon), also known as Chicon IV, was held September 2–6, 1982, at the Hyatt Regency Chicago in Chicago, Illinois, USA. The chairmen were Ross Pavlac and Larry Propp; Larry Smith and Bob Hillis were vice-chairmen. The guests of honor were A. Bertram Chandler (pro), Frank Kelly Freas (pro), and Lee Hoffman (fan). The toastmaster was Marta Randall. Total attendance was 4,275.