Al Pacino Don Michael Corleone Robert Duvall Tom Hagen Diane Keaton Kay Corleone Robert De Niro Vito Corleone John Cazale Frederico 'Fredo' Corleone Talia Shire Constanzia 'Connie' Corleone Lee Strasberg Hyman Roth Michael V. Gazzo Frank Pentangeli Richard Bright Al Neri Gastone Moschin Don Fanucci Tom Rosqui Rocco Lampone Bruno Kirby Young Clemenza Frank Sivero Genco Abbandando Francesca De Sapio Young Mama Corleone Morgana King Mama Corleone Marianna Hill Deanna Corleone Leopoldo Trieste Signor Roberto Dominic Chianese Jr. Johnny Ola Amerigo Tot Michael's Bodyguard Troy Donahue Merle Johnson John Aprea Young Tessio Joe Spinell William 'Willie' Cicci G.D. Spradlin Sen. Pat Geary Abe Vigoda Salvatore 'Sal' Tessio Tere Livrano Theresa Hagen James Caan