Joseph Smith was educated at Yardley secondary school and Birmingham Municipal Technical School, he served an apprenticeship with the Austin Motor Company and was then given a position of junior draughtsman in the aircraft department. In 1921 he moved to Vickers-Armstrongs as a senior draughtsman, becoming chief draughtsman five years later. Working under Mitchell, Smith was heavily involved with the early design of the Spitfire and was appointed Chief Designer after Mitchell's death in 1937. Smith continued development of the Spitfire and was later involved with designing the Supermarine Spiteful, Supermarine Seafang, Supermarine Attacker, and other Supermarine aircraft. Smith was appointed as a special director of Vickers-Armstrongs Ltd in 1948 and served as chairman of the board of the Society of British Aircraft Constructors from 1948 to 1951. In 1950 he was awarded the silver medal of the Royal Aeronautical Society. He died at Chandler's Ford on 20 February 1956.