Stewart was a senior lecturer and Head of the Department of Health, Physical Education and Outdoor Education at the University of Melbourne from 1995 to 2003. He has held numerous administrative positions at the University of Melbourne, including departmental Chair of the Human Ethics Committee and Associate Dean of the School of Visual and Performing Arts. In 2004 Stewart joined Arcadia University as Coordinator of Orientation Programs. In 2006 Stewart became Director of Student Life for Arcadia's study abroad programs in Australia, and he currently is Field Studies Coordinator.
Stewart teaches two academic courses for Arcadia; the J-Term course and a summer program. Stewart's research interests include environmental education, experiential education, environmental psychology and sports psychology. He has published numerous papers in these areas and is currently co-authoring an environmental education book.