Which Allied commander signed the Japanese Instrument of Surrender on behalf of the Allied nations?

Douglas MacArthur signed the Japanese Instrument of Surrender on behalf of the Allied nations.

MacArthur was Supreme Commander for the Allied Powers and presided over the ceremony aboard USS Missouri on September 2, 1945. He signed after the two Japanese representatives and before the other Allied signatories. His signature formally recorded the surrender of Japan under the authority of the Allied powers.

Fleet Admiral Chester W. Nimitz then signed as the United States representative, so Nimitz is a common alternative answer but not the commander who signed for all the Allies. Representatives of China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand followed. MacArthur later directed the Allied occupation of Japan and worked with Emperor Hirohito and the Japanese government during the country's postwar reconstruction. The ceremony's brief, carefully arranged sequence emphasized the distinction between Japan's representatives and the several Allied governments.