General Sir Francis George "Frank" Hassett (11 April 1918 – 11 June 2008) was an Australian general who rose to the position of Chief of the Defence Force Staff, the professional head of the Australian Defence Force, serving in this capacity from November 1975 until April 1977. Hassett joined the Australian Army in 1935 upon gaining entrance into the Royal Military College, Duntroon. Serving with distinction in the early stages of the Second World War, he was promoted to lieutenant colonel in 1942 at the age of 23, and posted as a staff officer for the remainder of the war.