What was the planned Allied invasion of Japan’s southern island Kyūshū called?

Operation Olympic was the planned Allied invasion of Japan’s southern island Kyūshū.

Olympic was the first phase of Operation Downfall, the overall Allied plan for invading the Japanese home islands. It was scheduled to begin on 1 November 1945, with Allied forces landing in southern Kyūshū. The captured territory would have provided airfields and staging areas for the second phase, Operation Coronet, aimed at the Kantō Plain near Tokyo.

The plan was canceled after Japan accepted surrender terms in August 1945. Its cancellation prevented what planners expected to be an exceptionally costly campaign. Allied intelligence anticipated fierce Japanese resistance, while Japan prepared Operation Ketsugō to defend Kyūshū with military forces and civilian mobilization.

Olympic is often confused with Downfall. Downfall was the umbrella operation; Olympic was its Kyūshū phase, and Coronet was the planned Honshū phase. None of these invasion operations took place because Japan surrendered before the scheduled landings.