The Twenty-second Amendment (Amendment XXII) to the United States Constitution limits the number of times a person is eligible for election to the office of President of the United States to two, and sets additional eligibility conditions for presidents who succeed to the unexpired terms of their predecessors.Until the amendment's ratification, the president had not been subject to term limits, but George Washington had established a two-term tradition that many other presidents followed. But in the 1940 and 1944 presidential elections, Franklin D. Roosevelt became the first president to win third and fourth terms, giving rise to concerns about a president serving unlimited terms. After Roosevelt's 1945 death, Republicans and conservative Democrats were swept into Congress in the 1946 elections and were in position to propose an amendment restricting the number of presidential terms. Congress approved the Twenty-second Amendment on March 21, 1947, and submitted it to the state legislatures for ratification. That process was completed on February 27, 1951, when the requisite 36 of the 48 states had ratified the amendment (neither Alaska nor Hawaii had yet been admitted as states), and its provisions came into force on that date.

The amendment prohibits anyone who has been elected president twice from being elected again. Under the amendment, someone who fills an unexpired presidential term lasting more than two years is also prohibited from being elected president more than once. Scholars debate whether the amendment prohibits affected individuals from succeeding to the presidency under any circumstances or whether it applies only to presidential elections.