The First Deadly Sin is a 1980 American crime thriller film produced by and starring Frank Sinatra. The film features Faye Dunaway, David Dukes, Brenda Vaccaro, James Whitmore, and Martin Gabel in his final role. The film also features Bruce Willis in his feature film debut as an uncredited extra. The film is based on the 1973 novel of the same name written by Lawrence Sanders. The screenplay was written by Mann Rubin.

The film originally was slated to be directed by Roman Polanski, who was dropped by Columbia Pictures after statutory rape charges were brought against him. Director Brian G. Hutton took over the production after Polanski fled to France.

The last of nine films produced by Sinatra, and his final starring role, he plays NYPD Sergeant Edward X. Delaney, a troubled veteran New York City Police Department homicide detective. In a supporting role, Dunaway is Delaney's ailing wife, hospitalized during the entire story with a rare kidney affliction.

The First Deadly Sin was the third production by Sinatra's Artanis production company and was shot on location in New York City. It premiered on October 23, 1980 at Loew's State Theatre in Times Square as part of a benefit for the Cabrini Medical Center, a key location in the film. The musical score was by composer and arranger Gordon Jenkins, who first worked with Sinatra on the 1957 album Where Are You?