What was the name of the planned Allied invasion operation canceled after Japan surrendered in 1945?

Operation Downfall was the planned Allied invasion of Japan that was canceled after Japan surrendered in 1945.

The proposed operation had two major stages. Operation Olympic was scheduled to land on southern Kyūshū in November 1945, while Operation Coronet was planned for the Kantō Plain near Tokyo in spring 1946. Together, these operations were intended to defeat Japan on its home islands.

Downfall was never executed. Japan's surrender followed the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war, and the Soviet invasion of Japanese-held Manchuria. The cancellation avoided the enormous casualties military planners expected from an invasion.

Operation Downfall is often confused with Olympic or Coronet. Those were component operations within the larger invasion plan. Downfall was the overall name, while Olympic and Coronet referred to its two principal phases.