Which U.S. president was in office when Japan signed its formal surrender?

Harry S. Truman was the U.S. president when Japan signed its formal surrender on September 2, 1945.

Truman became president on April 12, 1945, after Franklin D. Roosevelt died during his fourth term. He therefore led the United States during the final months of the war in Europe, the atomic bombings of Hiroshima and Nagasaki, Japan’s surrender announcement, and the formal signing aboard USS Missouri.

Truman publicly called for Japan’s surrender after the Hiroshima bombing and was informed of the Japanese decision to accept the Allied terms. His administration then oversaw the transition from wartime operations to the occupation of Japan and the broader postwar settlement.

Roosevelt is a common wrong answer because he led the United States for most of World War II and made key wartime decisions before his death. However, he died months before Japan’s surrender. Dwight Eisenhower was also a leading Allied commander, but he did not become president until 1953.