Lewis C. Cantley (born February 20, 1949) is an American cell biologist and biochemist and a professor in the Departments of Systems Biology and Medicine at Harvard Medical School, and the Director of Cancer Research at the Beth Israel Deaconess Medical Center, in Boston, Massachusetts. Among his research contributions are the discovery and study of the enzyme PI-3-kinase, now known to be important to understanding cancer and diabetes mellitus.He has recently moved to Weill Cornell Medical College in New York City.He received Canada Gairdner International Award in 2015.