What was the 1945 document that formally ended hostilities with Japan called?

The 1945 document that formally ended hostilities with Japan was called the Japanese Instrument of Surrender.

Representatives of the Japanese government and Imperial General Headquarters signed the document aboard USS Missouri in Tokyo Bay on September 2, 1945. It required Japan to accept the terms of the Potsdam Declaration and directed Japanese forces to cease resistance and surrender to designated Allied commanders.

The document was not a peace treaty. It was a formal capitulation, meaning that Japan accepted defeat and the military conditions imposed by the victorious Allies. A later agreement, the Treaty of San Francisco, restored Japan’s sovereignty and formally ended the state of war with many Allied countries in 1952.

Two versions of the surrender instrument were used during the ceremony: an Allied copy and a Japanese copy. A signing error by Canada’s representative caused the printed titles on one copy to be corrected by hand.