Douglas L. Coleman (6 October 1931 – 16 April 2014) was a scientist and professor at The Jackson Laboratory, in Bar Harbor, Maine. His work predicted that the ob gene encoded the hormone leptin, later co-discovered in 1994 by Jeffrey Friedman, Rudolph Leibel and their research teams at Rockefeller University. This work has had a major role in our understanding of the mechanisms regulating body weight and that cause of human obesity.