Fleming Crim is the John E. Willard and Hilldale Professor of Chemistry Emeritus at the University of Wisconsin-Madison. During a 40 career at the university, he chaired the department and led research in chemical reaction dynamics, using laser preparation of selected quantum states to control the course of chemical reactions. He spent 2013-2017 as an assistant director of the National Science Foundation (NSF) where he led the Directorate for Mathematical and Physical Sciences, overseeing programs in astronomy, chemistry, materials research, mathematics, and physics. He returned to NSF in 2018 to serve as the chief operating officer for three years.

Crim has served on and led committees of the American Chemical Society (ACS) and the American Physical Society (APS), and he chaired the Board on Chemical Sciences and Technology of the National Academies. He is a member of the National Academy of Sciences and the American Academy of Arts and Sciences and is a fellow of the ACS, APS, and the American Association for the Advancement of Science. Among other honors, he has received the Plyler Prize of the APS, the Langmuir Award of the ACS, and the Centenary Prize of the Royal Society of Chemistry (London). Crim received a B.S. in chemistry from Southwestern University and a Ph.D. from Cornell University. He worked in the semiconductor industry and was a post-doctoral staff member at Los Alamos National Laboratory prior to joining the University of Wisconsin.