The Treaty of San Francisco (サンフランシスコ講和条約, San-Furanshisuko kōwa-Jōyaku), also called the Treaty of Peace with Japan (日本国との平和条約, Nihon-koku to no Heiwa-Jōyaku), re-established peaceful relations between Japan and the Allied Powers on behalf of the United Nations by ending the legal state of war and providing for redress for hostile actions up to and including World War II. It was signed by 49 nations on 8 September 1951, in San Francisco, California, U.S. at the War Memorial Opera House. Italy and China were not invited, the latter due to disagreements on whether the Republic of China or the People's Republic of China represented the Chinese people. Korea was also not invited due to a similar disagreement on whether South Korea or North Korea represented the Korean people.It came into force on 28 April 1952, and legally ended the American-led Allied occupation of Japan. In Article 11, Japan accepted the judgments of the International Military Tribunal for the Far East and of other Allied War Crimes Courts imposed on Japan both within and outside Japan.This treaty ended Japan's role as an imperial power, allocated compensation to Allied and other civilians and former prisoners of war who had suffered Japanese war crimes during World War II, ended the Allied post-war occupation of Japan, and returned full sovereignty to it. This treaty relied heavily on the United Nations Charter and the Universal Declaration of Human Rights to enunciate the Allies' goals.

This treaty, along with the Security Treaty signed that same day, marks the beginning of the San Francisco System which defines Japan's relationship with the United States and its role in the international arena and characterizes Japan's post-war history.