Which Allied commander accepted Japan’s surrender on behalf of all the Allied powers?

Douglas MacArthur accepted Japan’s surrender on behalf of all the Allied powers.

MacArthur was the Supreme Commander for the Allied Powers and presided over the surrender ceremony on 2 September 1945. He signed the Instrument of Surrender first among the Allied representatives, acting in his official capacity rather than as the representative of the United States alone.

After MacArthur signed, Fleet Admiral Chester Nimitz signed for the United States. Representatives of China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand then signed for their governments.

MacArthur had commanded Allied forces in the Southwest Pacific Area and had returned to the Philippines in October 1944 after making his famous promise to return. Following the surrender, he supervised the Allied occupation of Japan. His position gave him authority over the occupation structure, although the Allied governments remained represented through the Allied Council and other institutions.