Colt 45 is a term used to designate two distinctly separate firearms produced by Colt's Manufacturing Company:
- The Single Action Army, also known as the Peacemaker—"the gun that won the West"
- The M1911, designed by John Browning and the official sidearm of the United States armed forces from 1911 to 1985
Colt 45 is also the name of a popular malt liquor brewed by the Pabst Brewing Company in the United States.