Donald Richard Ort is an American botanist and biochemist. He is the Robert Emerson Professor of Plant Biology and Crop Sciences at the University of Illinois at Urbana-Champaign where he works on improving crop productivity and resilience to climate change by redesigning photosynthesis. He is a member of the National Academy of Sciences (NAS) and a fellow of the American Association for the Advancement of Science (AAAS) and American Society of Plant Biologists (ASPB).