Ilse Clara Franziska Ipsen is a German-American mathematician who works as a professor of mathematics at North Carolina State University and as associate director of the Statistical and Applied Mathematical Sciences Institute, a joint venture of North Carolina State and other nearby universities.
Ipsen earned a diploma from the Kaiserslautern University of Technology in 1977, and completed her doctorate from the Pennsylvania State University in 1983 under the supervision of Don Heller. Her dissertation was Systolic Arrays for VSLI and concerned Very Large Scale Integration hardware implementations of the systolic array parallel computing architecture.
Ipsen is the author of the book Numerical Matrix Analysis: Linear Systems and Least Squares (SIAM, 2009), an introductory graduate textbook on the sensitivity analysis of computations in linear algebra.
In 2011, she became a fellow of the Society for Industrial and Applied Mathematics "for contributions to numerical linear algebra, perturbation theory, and applications." She was elected as a fellow of the American Association for the Advancement of Science in 2018.