HMAS Rushcutter is a former Royal Australian Navy (RAN) base that served as a depot, radar and anti-submarine training school located at Rushcutters Bay and Darling Point, in Sydney's eastern suburbs in New South Wales, Australia.

Originally the New South Wales headquarters of the Naval Brigade and naval artillery from 1901, the site was used as an administrative depot due to the demolition of Fort Macquarie as facilities for the compulsory peacetime training from 1911-1929.

The site remained as the Naval Reserve Depot and the Anti Submarine School was opened there in 1939 and used by the RAN and newly formed Anti-Submarine Branch of the Naval Reserve.

During World War II the site housed the Anti-Submarine School, the Radar and Gunnery Instruction School and served as a base for the mosquito fleet: Harbour Defence Motor Launches, the Fairmiles and the Naval Auxiliary Patrol Boats.

The technical functions of Radar operation remained at HMAS Rushcutter.