**Isadore Manuel Singer** (born May 3, 1924) is an American mathematician. He is an Institute Professor in the Department of Mathematics at the Massachusetts Institute of Technology. He is noted for his work with Michael Atiyah proving the Atiyah–Singer index theorem in 1962, which paved the way for new interactions between pure mathematics and theoretical physics.

Singer was born in Detroit, Michigan, and received his undergraduate degree from the University of Michigan in 1944. After obtaining his M.S. and Ph.D. from the University of Chicago in 1948 and 1950 respectively, he taught at UCLA and MIT, where he has spent the majority of his career.

He was chair of the Committee of Science & Public Policy of the United States National Academy of Sciences, a member of the White House Science Council (1982–88), and on the Governing Board of the United States National Research Council (1995–99).

Singer is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. He is a member of the Norwegian Academy of Science and Letters. In 2012 he became a fellow of the American Mathematical Society.

Among the awards he has received are the Bôcher Memorial Prize (1969) and the Steele Prize for Lifetime Achievement (2000), both from the American Mathematical Society, the Eugene Wigner Medal (1988), the National Medal of Science (1983), the Abel Prize (2004, shared with Michael Atiyah), the 2004 Gauss Lecture and the James Rhyne Killian Faculty Achievement Award from MIT (2005).

*Quantum field theory, supersymmetry, and enumerative geometry*. Freed, Daniel S. and Morrison, David R. and Singer, Isadore editors. IAS/Park City Mathematics Series, Vol. 11. American Mathematical Society Providence, RI viii+285. Papers from the Graduate Summer School of the IAS/Park City Mathematics Institute held in Princeton, NJ, 2001. (2006)