Popularly viewed as one of the best American films ever made, the multi-generational crime saga The Godfather is a touchstone of cinema: one of the most widely imitated, quoted, and lampooned movies of all time. Marlon Brando and Al Pacino star as Vito Corleone and his youngest son, Michael, respectively. It is the late 1940s in New York and Corleone is, in the parlance of organized crime, a "godfather" or "don," the head of a Mafia family. Michael, a free thinker who defied his father by enlisting in the Marines to fight in World War II, has returned a captain and a war hero. Having long ago rejected the family business, Michael shows up at the wedding of his sister, Connie (Talia Shire), with his non-Italian girlfriend, Kay (Diane Keaton), who learns for the first time about the family "business." A few months later at Christmas time, the don barely survives being shot by gunmen in the employ of a drug-trafficking rival whose request for aid from the Corleones' political connections was rejected. After saving his father from a second assassination attempt, Michael persuades his hotheaded eldest brother, Sonny (James Caan), and family advisors Tom Hagen (Robert Duvall) and Sal Tessio (Abe Vigoda) that he should be the one to exact revenge on the men responsible.

After murdering a corrupt police captain and the drug trafficker, Michael hides out in Sicily while a gang war erupts at home. Falling in love with a local girl, Michael marries her, but she is later slain by Corleone enemies in an attempt on Michael's life. Sonny is also butchered, having been betrayed by Connie's husband. As Michael returns home and convinces Kay to marry him, his father recovers and makes peace with his rivals, realizing that another powerful don was pulling the strings behind the narcotics endeavor that began the gang warfare. Once Michael has been groomed as the new don, he leads the family to a new era of prosperity, then launches a campaign of murderous revenge against those who once tried to wipe out the Corleones, consolidating his family's power and completing his own moral downfall. Nominated for 11 Academy Awards and winning for Best Picture, Best Actor (Marlon Brando), and Best Adapted Screenplay, The Godfather was followed by a pair of sequels.