| Actor | Character | Firearm | Notes |
|---|---|---|---|
| Al Pacino | Michael Corleone | Smith & Wesson Model 36 | with K/L frame grips |
| Angelo Infanti | Fabrizio | Double Barreled Shotgun | - |
| Franco Citti | Calo | Double Barreled Shotgun | - |
| James Caan | Santino "Sonny" Corleone | Smith & Wesson Model 36 | . |
| Joe Spinell | Willi Cicci | M1911A1 | Uncredited |
| John Cazale | Fredo Corleone | Smith & Wesson Model 36 | nickel |
| Lenny Montana | Luca Brasi | Smith & Wesson Model 27 | snubnose |
| Randy Jurgensen | One of the Barzini assasins | Colt 1921A Thompson | - |
| Richard Bright | Al Neri | Smith & Wesson Victory Model | - |
| Richard S. Castellano | Peter Clemenza | Smith & Wesson Model 10 | - |
| Richard S. Castellano | Peter Clemenza | 12 Gauge Double Barreled Shotgun | - |
| Tom Rosqui | Rocco Lampone | Madsen M50 | - |