Missingham studied in Perth with JWR Linton and AB Webb (1922 –1926), in Paris (1926) and in London (1926-1932). An artist of wide experience and versatile talents working in varied media, he became interested in photography in 1933. Missingham visited Canada from 1927 to 1928 where he worked as a teacher and freelance artist. He returned to Australia to live in 1941. In 1945 he was appointed director of the Australian Gallery of New South Wales, entering the period of administrative work for which he is best known. He introduced enlightened policies of Australian art collecting, and the international exhibitions organised by him represented outstanding contributions to contemporary Australian art development. His long administrative career, 1945 to 1971, was climaxed by his supervision of the new building extensions to the Gallery.