The Treaty of San Francisco took effect on 28 April 1952, formally ending the Allied occupation of Japan.
Japan’s surrender in 1945 ended the fighting, but it did not immediately restore full sovereignty. The occupation began in 1945 under the authority of the Supreme Commander for the Allied Powers, with the United States exercising the dominant role in administration and reform.
The peace treaty was signed in San Francisco on 8 September 1951 by Japan and many Allied countries. It entered into force on 28 April 1952, ending the occupation and restoring Japan’s independence in relations with those treaty members.
This date is often confused with 2 September 1945, when Japan signed the Instrument of Surrender, or 15 August 1945, when the emperor’s surrender announcement was broadcast. Those dates mark the end of the war’s immediate military phase, not the end of the occupation.