John Crace was a senior Australian naval officer during the Second World War. He was born on 6 February in the area of New South Wales that later became Gungahlin in the Australian Capital Territory. He began his schooling at the Kings School at Parramatta in Sydney but completed his education in England before joining the Royal Navy's training ship HMS Britannia in May 1902.

In the first decade of his naval career, Crace specialised as a torpedo officer and made several returns to Australia on postings. He married Carola Baird in Glasgow in April 1920 and between then and the beginning of the Second World War, he served on both shore and sea postings, all the while rising steadily through the ranks. By September 1939 he had been promoted to rear admiral and appointed to command the Australian Squadron. On arriving in Sydney he found, however, that most of Australia's naval vessels were operating far from Australia's shores.

Frustrated at the lack of activity and annoyed at the Naval Board's perceived interference in operational matters, Crace tried to resign after two years in the post. However, when the war against Japan began he became commander of the Allied Naval Squadron, ANZAC Force. He served on operations in the waters around New Guinea but was unhappy that his ships were given a minor role compared to those of the United States Navy. He then served during the Battle of the Coral Sea in May 1942 but was in a position peripheral to the main action.

He returned to England in June 1942 having handed over his command. Crace then became Superintendent of Chatham Naval Dockyard; he held that position until July 1946. He retired to Hampshire where he died on 11 May 1968.