Douglas MacArthur signed the Japanese Instrument of Surrender immediately after Japan’s representatives.
MacArthur signed at about 9:08 a.m. aboard USS Missouri, after Mamoru Shigemitsu and Yoshijiro Umezu had signed for the Japanese government and Imperial General Headquarters. He signed as Supreme Commander for the Allied Powers and accepted Japan’s surrender on behalf of the Allied nations.
MacArthur had been appointed Supreme Commander for the Allied Powers after Japan’s acceptance of the surrender terms. He oversaw the occupation and reconstruction of Japan, making his role at the ceremony both military and political.
Fleet Admiral Chester Nimitz signed next as the United States representative. This sequence can cause confusion: MacArthur represented the Allied powers in his capacity as supreme commander, while Nimitz signed separately for the United States. MacArthur also delivered opening and closing remarks, but the document itself was signed by multiple representatives from Japan and the Allied nations.