Roy Greenlee was a chemist at the University of Chicago Metallurgical Lab and at Oak Ridge, Tennessee. In Chicago, Greenlee worked on plutonium separation under Glenn Seaborg, specifically on calculating the half-life of Pu-240. After leaving Chicago for Oak Ridge in 1944, Greenlee contributed to the design for liquid thermal separation of U-235.
Greenlee left the Manhattan Project in November 1945 for a career in petroleum production with the Battelle Institute and Petrolite Corporation. He is a graduate of Ohio State University and a former secretary for the American Society for Testing and Materials (ASTM).