HMAS Cerberus is a Royal Australian Navy (RAN) base that serves as the primary training establishment for RAN personnel. The base is located adjacent to Crib Point on the Mornington Peninsula, south of the Melbourne City Centre, Victoria, Australia. The base is also an official bounded locality of the Shire of Mornington Peninsula and is the only naval base to have a specific listing in the Australian census. HMAS Cerberus recorded a population of 1,124 at the 2021 census. A section of the base centred around the Parade Ground was added to the Australian Commonwealth Heritage List on 22 June 2004, known as the HMAS Cerberus Central Area Group.

The site for the Cerberus naval base on Hanns Inlet, between Sandy Point and Stony Point on Western Port Bay was purchased in 1911. The 15 square kilometres (5.8 sq mi) base was opened in September 1920 and became known as Flinders Naval Depot in 1921. The Post Office opened on 2 December 1912 as Flinders Naval Base, was renamed Flinders Naval Depot in 1925 and HMAS Cerberus, Westernport in 1963. Cerberus now occupies most of Stony Point to the north and all of Sandy Point in the south.

From 1930 until 1958, Cerberus was the home of the Royal Australian Naval College, until it was clear that the base was becoming overcrowded and the College was moved back to HMAS Creswell. With the outbreak of World War II, many temporary buildings were erected to facilitate the training of wartime recruits. Many of these buildings were later demolished or replaced.

HMAS Cerberus possesses an oceanic climate (Köppen: Cfb), with tepid, relatively dry summers and mild, wetter winters. Average maxima vary from 24.9 °C (76.8 °F) in February to 13.7 °C (56.7 °F) in July, while average minima fluctuate between 14.2 °C (57.6 °F) in February and 6.3 °C (43.3 °F) in July. Mean precipitation is moderately low, averaging 710.8 mm (27.98 in) per annum, but rainfall is frequent, as HMAS Cerberus receives 169.1 precipitation days annually (with a maximum frequency of rain in winter). Extreme temperatures have ranged from 45.8 °C (114.4 °F) on 7 February 2009 to −3.0 °C (26.6 °F) on 3 July 2017.

The primary role of HMAS Cerberus has always been the training of RAN personnel. With the establishment of four tri-service schools over the last 13 years, this role has been extended to training Army and Air Force personnel. Specific courses offered include: the School of Survivability and Ship Safety which specialises in fire fighting, damage control and nuclear/biological/chemical defence; and seamanship and weapons training.

The base is also the home of the Recruit School – for all sailors their first contact with life in the RAN. HMAS Cerberus comprises numerous training and recreation facilities, two chapels and a small marina. Training is provided for about 6,000 personnel annually, averaging 800 trainees at any one time.

HMAS Cerberus currently host to the following naval training schools

HMAS Cerberus hosts the only dedicated weather-related Satellite Earth station in Australia, founded in 1991 and operated by the Bureau of Meteorology (BoM) to service China's first Turn Around Ranging Station (C-TARS) and servicing geostationary meteorological satellites, servicing Japan's Himawari or GMS-4 and GMS-5. In August [2016], the BoM installed through a contractor Av-Comm, the first Australian ground station for the Himawari 8 weather satellite service.