Martin Chalfie (born January 15, 1947) is an American scientist. He is the William R. Kenan, Jr. Professor of Biological Sciences at Columbia University, where he is also chair of the department of biological sciences.He shared the 2008 Nobel Prize in Chemistry along with Osamu Shimomura and Roger Y. Tsien "for the discovery and development of the green fluorescent protein, GFP. He holds a Ph.D. in neurobiology from Harvard University.