What was the overall Allied plan for invading Japan’s home islands in 1945 called?

The overall Allied plan for invading Japan’s home islands was called Operation Downfall.

Downfall was a proposed United States and British Empire invasion plan that would have been carried out if Japan continued fighting. It had two major stages: Operation Olympic, aimed at southern Kyushu, and Operation Coronet, aimed at the Kanto Plain near Tokyo. The plan was canceled after Japan surrendered in August 1945.

Operation Downfall would have required enormous forces, shipping, air support, and preparations. Planners expected fierce resistance because Japan was organizing for a defense of the home islands. The plan’s cancellation meant that Olympic and Coronet never took place. Downfall is therefore a planned operation rather than a campaign that occurred. Its existence is sometimes confused with the atomic bombings or with the broader Allied occupation, but it specifically referred to the contemplated invasion of Japan itself.