Mark Alfred Tester (born 6 March 1963 in Tasmania) is an Australian botanist and professor of plant science at King Abdullah University of Science and Technology, where he is also associate director of the Center for Desert Agriculture.
Prior to joining King Abdullah University of Science and Technology in February 2013, he was a professor of plant physiology at the University of Adelaide and the Australian Centre for Plant Functional Genomics from 2009 to 2013.