Operation Olympic targeted Kyūshū as the first planned phase of Operation Downfall.
The Allied plan called for an invasion of southern Kyūshū on 1 November 1945. Capturing the island’s southern area would have provided airfields and bases for the next phase, Operation Coronet, which was aimed at the Kantō Plain near Tokyo.
Operation Olympic was never carried out because Japan surrendered in August 1945. The proposed invasion would have involved a very large Allied naval and ground force, with Okinawa serving as an important staging area.
Kyūshū was chosen because it was the southernmost of Japan’s four main islands and lay within reach of Allied bases. The planned operation is sometimes confused with Coronet, but Olympic meant the attack on Kyūshū, while Coronet meant the later attack near Tokyo.