What was the name of the planned first phase of the Allied invasion of Japan?

Operation Olympic was the planned first phase of the Allied invasion of Japan.

Olympic called for an amphibious assault on southern Kyūshū, one of Japan's four main home islands. The operation was scheduled for November 1, 1945, and was intended to seize airfields and establish bases for later operations against the rest of Japan.

It formed part of Operation Downfall, the broader invasion plan. The second phase, Operation Coronet, was planned for March 1946 and would have targeted the Kantō Plain on Honshū, near Tokyo.

Olympic never occurred because Japan surrendered in August 1945. Its planned scale reflected Allied expectations of fierce resistance, although the exact predicted casualties and likely course of the invasion remain subjects of historical debate. Olympic should not be confused with Coronet, which was the later phase.