The ash heap of history (or often garbage heap of history or dustbin of history) is a figurative place to where objects such as persons, events, artifacts, ideologies, etc. are relegated when they are forgotten or marginalized in history.

The expression—or something like it—arose in the 19th century in various places. But it was popularized by Leon Trotsky in response to the Mensheviks walking out of the Petrograd Second Congress of Soviets, on October 25, 1917 (Julian calendar), thereby enabling the Bolsheviks to establish their dominance. Trotsky declared: "'You are pitiful, isolated individuals! You are bankrupts. Your role is played out. Go where you belong from now on—into the dustbin of history!'"

It has since been used in both the direct and the ironic sense in political and nonpolitical contexts.

It was used by Ronald Reagan in a speech to the British House of Commons on June 8, 1982. Reagan's speechwriter, Tony Dolan, chose the expression deliberately because of its prior context. His exact phrase was: "... freedom and democracy will leave Marxism and Leninism on the ash heap of history."