Victor William Guillemin (born 1937, Boston) is a mathematician, a leader in the field of symplectic geometry, who has also made fundamental contributions to the fields of microlocal analysis, spectral theory, and mathematical physics. He has strongly influenced many graduate students and postdoctoral visitors at the Massachusetts Institute of Technology, where he is a tenured Professor in the Department of Mathematics, and where he has supervised over 40 doctoral students.
Guillemin received a Ph.D. in mathematics from Harvard University in 1962, after earlier completing his B. A. at Harvard in 1959, as well as an M. A. at the University of Chicago in 1960. His thesis, entitled Theory of Finite G-Structures, was written under the direction of Shlomo Sternberg.
He was elected to the United States National Academy of Sciences in 1985. In 2003, he was awarded the Leroy P. Steele Prize for Lifetime Achievement by the American Mathematical Society. He is the author or co-author of numerous books and monographs, including a widely used textbook on differential topology, written jointly with Alan Pollack.