Michael Hartley Freedman (born April 21, 1951) is an American mathematician, at Microsoft Station Q, a research group at the University of California, Santa Barbara. In 1986, he was awarded a Fields Medal for his work on the 4-dimensional generalized Poincaré conjecture. Freedman and Robion Kirby showed that an exotic ℝ4 manifold exists.
Freedman was born in Los Angeles, California, in the United States His father, Benedict Freedman, was an American Jewish aeronautical engineer, musician, writer, and mathematician. His mother, Nancy Mars Freedman, performed as an actress and also trained as an artist. His parents cowrote a series of novels together. He entered the University of California, Berkeley, and after two semesters dropped out. In the same year he wrote a letter to Ralph Fox, a Princeton professor at the time, and was admitted to graduate school so in 1968 he continued his studies at Princeton University where he received Ph.D. degree in 1973 for his doctoral dissertation titled Codimension-Two Surgery, written under the supervision of William Browder. After graduating, Freedman was appointed a lecturer in the Department of Mathematics at the University of California, Berkeley. He held this post from 1973 until 1975, when he became a member of the Institute for Advanced Study (IAS) at Princeton. In 1976 he was appointed assistant professor in the Department of Mathematics at the University of California San Diego. He spent the year 1980/81 at IAS, returning to UC San Diego, where in 1982 he was promoted to professor. He was appointed the Charles Lee Powell chair of mathematics at UC San Diego in 1985.
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 a fellow of the American Academy of Arts and Sciences and of the American Mathematical Society. In addition to winning a Fields Medal at the International Congress of Mathematicians (ICM) in 1986 in Berkeley, he was an Invited Speaker at the ICM in 1983 in Warsaw and at the ICM in 1998 in Berlin. He currently works at Microsoft Station Q at the University of California, Santa Barbara, where his team is involved in the development of the topological quantum computer.