Operation Olympic was planned to invade Kyushu in late 1945.
Kyushu is Japan’s southernmost main island, and Allied planners intended to seize its southern third during the opening phase of Operation Downfall. The planned landings were scheduled for November 1945, several months after the end of the Battle of Okinawa.
Capturing Kyushu would have provided airfields and a forward base for the next phase, Operation Coronet. Coronet was planned for the Kanto Plain on Honshu, the island containing Tokyo, in spring 1946.
Japan’s military expected an invasion and prepared defenses under Operation Ketsugo. The projected battle never occurred because Japan accepted the Potsdam Declaration and signed the Instrument of Surrender. The names Olympic and Coronet therefore refer to canceled operations, not battles that were fought.