Charles L. Epstein is a Senior Research Scientist in the Center for Computational Mathematics at the Flatiron Institute. He was the Thomas A. Scott Professor of Mathematics Emeritus at the University of Pennsylvania, Philadelphia.

Charles Epstein is an analyst and applied mathematician. His research interests include partial differential equations, mathematical physics, boundary value problems, mathematical biology, population genetics, nuclear magnetic resonance and medical imaging, and numerical analysis; he has also worked in hyperbolic geometry, univalent function theory, several complex variables, microlocal analysis and index theory.

He was an undergraduate in mathematics at the Massachusetts Institute of Technology and graduate student at the Courant Institute, New York University, where he received his Ph.D. in 1983 under the direction of Peter Lax.

He was a postdoc with William Thurston before moving to the University of Pennsylvania, where he has been since. Epstein won a Sloan Research Fellowship in 1988.

He is currently a Senior Research Scientist in the Center for Computational Mathematics at the Flatiron Institute, New York City, and was the Thomas A. Scott Professor of Mathematics Emeritus at the University of Pennsylvania, Philadelphia.

In 2014, Charles Epstein became a Fellow of the American Mathematical Society "for contributions to analysis, geometry, and applied mathematics including medical imaging, as well as for service to the profession". He was a co-recipient of the Stefan Bergman Prize in 2016.