Michael Hartley Freedman (born 21 April 1951 in Los Angeles, California, U.S.) is a mathematician at Microsoft Station Q. In 1986, he was awarded a Fields Medal for his work on the Poincaré conjecture. Freedman and Robion Kirby showed that an exotic R4 manifold exists. Freedman has received numerous other awards and honors including Sloan and Guggenheim Fellowships, a MacArthur Fellowship and the National Medal of Science. He is an elected member of the National Academy of Sciences, and the American Academy of Arts and Sciences.