A master surgeon and teacher, Gallie was born in Barrie and educated at the University of Toronto. In 1906, after serving internships in Toronto and New York hospitals, he joined the staff of the Hospital for Sick Children in Toronto. There Gallie conducted extensive clinical research on tendon fixation, the repair of bone and the transplantation of tissue as 'living sutures', devising and perfecting revolutionary techniques now used all over the world. As Professor of Surgery (1929-47) and Dean of the Faculty of Medicine (1936-46) at the University of Toronto, he developed the first systematic training program for surgeons in Canada and produced many graduates who later gained renown. Well-regarded by his peers, Gallie received numerous honours for his outstanding contributions to medical science.