What was the name of the Allied plan for a full-scale invasion of Japan in 1945?

Operation Downfall was the Allied plan for a full-scale invasion of Japan in 1945.

The plan was divided into two major stages. Operation Olympic was intended to land on Kyushu in November 1945, while Operation Coronet was planned for the Kanto Plain near Tokyo in March 1946. Together, these operations formed Operation Downfall.

Allied planners expected extremely heavy resistance. Japan had mobilized military personnel and civilian defense groups, and its leaders were preparing for a final battle on the home islands. The projected invasion required enormous numbers of troops, ships, aircraft, and supplies.

Japan’s surrender in August 1945 meant that Downfall was never carried out. Because Olympic and Coronet were component operations, they are sometimes incorrectly treated as alternative names for the entire invasion plan. Downfall is the broader name for the proposed campaign, not the name of either individual landing operation.