Operation Olympic was the Allied codename for the planned November 1945 invasion of Kyushu.
It formed the first stage of Operation Downfall, the projected invasion of Japan’s home islands. The plan called for American forces to land on Kyushu on November 1, 1945, seize airfields and ports, and use the island as a base for later operations.
The second stage was Operation Coronet, planned for March 1, 1946, against the Kantō Plain on Honshu near Tokyo. These plans were never carried out because Japan accepted the Allied surrender terms in August 1945 and formally signed the Instrument of Surrender on September 2.
Operation Olympic is often confused with Operation Overlord, the codename for the Allied invasion of Normandy in June 1944. It is also important not to describe Olympic as an actual battle: it was a planned operation that became unnecessary after Japan surrendered.