What official title did Douglas MacArthur hold when he accepted Japan’s surrender in 1945?

Douglas MacArthur held the title Supreme Commander for the Allied Powers when he accepted Japan’s surrender in 1945.

MacArthur signed the Japanese Instrument of Surrender on behalf of the Allied powers at the ceremony aboard USS Missouri on September 2, 1945. His signature appeared after those of Japan’s two principal signatories and before the representatives of the individual Allied governments.

The title reflected MacArthur’s authority over the Allied occupation and the military arrangements connected with Japan’s defeat. He had already served as commander of Allied forces in the Southwest Pacific Area and had directed major operations across New Guinea and the Philippines.

MacArthur’s role at the ceremony is sometimes described simply as “Allied commander,” but the formal title printed on the document was Supreme Commander for the Allied Powers. After the surrender, he led the occupation of Japan and oversaw sweeping political, legal, and social reforms.