Naval Base Perth was a United States Navy base at Perth, Western Australia. There were several Naval facilities at Perth during World War II. Perth on southwestern Australia was selected as the site for US Naval base as it is out of reach of Empire of Japan's long-range bombers. Bombing of Darwin on February 19, 1942, demonstrated a more southern port was needed. Both existing port facilities and new bases were built at Perth. Naval Base Perth's Fleet Post Office # was 255 SF Perth, Australia.