Dirty Harry is a 1971 American action thriller film produced and directed by Don Siegel, the first in the Dirty Harry series. Clint Eastwood plays the title role, in his first outing as San Francisco Police Department (SFPD) detective "Dirty" Harry Callahan. The film drew upon the actual case of the Zodiac Killer as the Callahan character seeks out a similar vicious psychopath.
Dirty Harry was a critical and commercial success and set the style for a whole genre of police films. It was followed by four sequels: Magnum Force in 1973, The Enforcer in 1976, Sudden Impact in 1983 (directed by Eastwood himself), and The Dead Pool in 1988.
In 2012, the film was selected for preservation in the National Film Registry by the Library of Congress for being "culturally, historically, and aesthetically significant." The film's critical reputation has grown in stature and it is commonly listed among the greatest films of all time.