Stephen James Simpson ACFRS FAA (born 26 June 1957) is the Executive Director of Obesity Australia and is the Academic Director of the Charles Perkins Centre.
Born in Australia, he graduated with a BSc from the University of Queensland in 1978, and completed his PhD at King's College London in 1982 on locust feeding physiology. He spent 22 years in Oxford, in Experimental Psychology, the Department of Zoology, and the University Museum of Natural History, before returning to Australia in 2005, in the School of Biological Sciences at Sydney University.
He was awarded the Wigglesworth Medal of the Royal Entomological Society in 2011 and was made a Companion of the Order of Australia in 2015. He was elected a Fellow of the Royal Society in 2013 and is also a Fellow of the Australian Academy of Science.