Joseph Burnett was born at Singleton, New South Wales, on 26 December 1899 and became captain of HMAS Sydney in 1941. As a youth he attended Singleton Primary School and in 1912 applied to enter the Royal Australian Naval College in Geelong, becoming one of its first entrants as a cadet midshipman on 31 December 1912.
Having graduated in 1917, he was sent to England where he joined HMAS Australia, on which he served until the end of the First World War, reaching the rank of sub-lieutenant. For much of the next seven years Burnett served with the Royal Navy in England, was promoted to lieutenant in January 1920, and qualified as a gunnery officer in 1922. During his time in England Burnett proved himself an excellent sportsman, representing the United Services and the Royal Navy in rugby and performing well in tennis, cricket, and athletics.
In 1924 he was appointed gunner officer on HMAS Adelaide, in the same year he married Enid Ward and returned to Australia. After three years in Australia he returned to England in 1927, was promoted to lieutenant commander in 1928, and began service on HMAS Canberra. Further service in England followed and Burnett attended the Naval Staff College at Greenwich in 1932-33. Having been promoted to commander in December 1932, he returned to Australia and began two years of service at the Navy Office in Melbourne in 1933.
Burnett returned to sea in 1936 with a posting to HMAS Canberra as Executive Officer. The following year he returned to England for the last time, becoming Executive Officer on the battleship HMS Royal Oak. In December 1938 he was promoted to captain and the following year completed the Imperial Defence College course. When the Second World War began he was recalled to Australia and appointed Assistant Chief of Naval Staff at the Navy Office in Melbourne.
A highly regarded officer who received uniformly good reports throughout his career, Burnett was sent to Singapore in October 1940 as senior RAN representative at an Allied conference considering the defence of the Asia-Pacific region. He was instrumental in the formation Naval Auxilliary Patrol, which was used to patrol harbour entrances during the war. In May 1941 he was given command of HMAS Sydney.
Having commanded the ship on convoy duties, Burnett was bringing Sydney back to Fremantle on 19 November 1941 when she encountered the German raider Kormoran. In the ensuing action Kormoran was sunk and a damaged Sydney was seen sailing over the horizon before she disappeared with the loss of all on board.