Professor Anthony John Ryan (born 1962) OBE FRSC is an English polymer chemist and sustainability leader at the University of Sheffield. He was Pro-Vice-Chancellor of the university's Faculty of Science from 2008 until 2016, and is currently Director of the Grantham Centre for Sustainable Futures. He delivered the 2002 Royal Institution Christmas Lectures and has appeared on programmes including the BBC Radio 4 comedy and popular science series The Infinite Monkey Cage. He has collaborated on a range of arts and sciences projects with Professor Helen Storey from the London College of Fashion, University of the Arts London.