Stewart was born in Adelaide, 1952, where he developed a love for art at school. On leaving school he committed to practice enthusiastically; he travelled throughout Australia, Asia and Europe and, although largely self taught, completed several painting courses on returning home.
His main practice has been painting in oils, although he has extended his skills to include sculpture and installation. During his development years, Stewart was greatly influenced by Fred Williams and John Olsen, among others. In later years his influences have included the art of Friedensreich Hundertwasser, Austrian artist and architect, and the intimate relationship that Indigenous Australians have with their land.