Ian Rutherford Plimer (born 12 February 1946) is an Australian geologist, professor emeritus of earth sciences at the University of Melbourne, previously a professor of mining geology at the University of Adelaide, and the director of multiple mineral exploration and mining companies.
He has published many scientific papers, six books and is one of the co-editors of Encyclopedia of Geology.
He has been a critic of creationism, and he denies that greenhouse gases cause climate change.