Holsworthy military base (ICAO: YSHW) is an Australian Army military barracks, located in the Heathcote National Park in Holsworthy approximately 25 km (16 mi) from the central business district, in south-western Sydney, New South Wales, Australia. The barracks is part of the Holsworthy military reserve, which is 22,000 ha (54,000-acre) training area and artillery range for the Australian Army, established in the 1880s and been in active use since World War I. Following World War II, it became a major base for the permanent component of the Australian Army in New South Wales. Holsworthy Military Airport is also located in the reserve. Activities carried out on the base include the use of firing ranges, chemical weapons testing, fire training, vehicle maintenance, and bulk chemical storage and distribution from numerous above ground and underground storage tanks.Following the movement of many units of the Regular Army to Darwin, Northern Territory, in the late 1990s, many Army Reserve units were moved from other depots to Holsworthy Barracks, including the Headquarters of the 5th Brigade.The base is currently home to 142 Signal Squadron, 2nd Commando Regiment (2 Cdo Regt), Special Operations Engineer Regiment and 6th Aviation Regiment. A number of training units and the Defence Force Correctional Establishment are also located at Holsworthy.
The base is also home to the regional headquarters of both NSW Australian Army Cadets Brigade and NSW 2nd Australian Army Cadets Brigade.