He studied at the Croydon College of Art (1965-1968) and Newcastle University (1968-1972). He then studied at Harvard University in the United States where he settled in 1975 and became an American citizen in 1983. He was nominated for the Turner Prize in 1989 and 1983. He has exhibited very widely in the United States and Europe. His work is represented in private and public collections worldwide, including the collections of many museum and public galleries, including the Museum of Modern Art and the Guggenheim Museum in New York, the National Gallery of Art and the Smithsonian American Art Museum in Washington D.C., the Fine Arts Museums of San Francisco, the National Gallery of Australia, the Tate Gallery, London, the Irish Museum of Modern Art in Dublin. In 2006 Scully donated eight of his paintings to the Hugh Lane Gallery Dublin.