Nine Allied governments, besides MacArthur’s Supreme Allied command, signed Japan’s surrender instrument.
The governments represented were the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand. Their representatives signed after General Douglas MacArthur accepted the surrender as Supreme Commander for the Allied Powers.
Fleet Admiral Chester Nimitz signed for the United States. The other representatives included General Hsu Yung-chang for China, Admiral Sir Bruce Fraser for the United Kingdom, Lieutenant General Kuzma Derevyanko for the Soviet Union, and senior officers from the other five Allied countries.
Counting can be confusing because MacArthur also represented the Allied powers in the ceremony, while Nimitz separately signed for the United States. The nine-government count refers to the national representatives who signed after MacArthur. The Japanese side had two actual signers, supported by a larger delegation.