Trevor John McDougall AC FRS FAA FAGU FInstP FRSN is a physical oceanographer specialising in ocean mixing and the thermodynamics of seawater. He is Scientia Professor of Ocean Physics in the School of Mathematics and Statistics at the University of New South Wales, Sydney, Australia. He is President of the International Association for the Physical Sciences of the Oceans (IAPSO) of the International Union of Geodesy and Geophysics.