Karen C. Lassey

Instructor in Mathematics
Assistant Principal
Karen C. Lassey


B.A. Amherst College

M.S.T University System of New Hampshire

Ed.D. University of Pennsylvania


Karen Lassey has taught at Phillips Exeter Academy since 1996. Before coming to Exeter, she served in the United States Army and taught at the Army Engineer School.

At Exeter, she has taught in both the Science and Mathematics Departments. She has also taught summer math courses for neighboring school districts and on campus in the Exeter Summer program.

Through the Exeter Math and Humanities Institutes, and the Anja Greer Math, Science and Technology Conference, she has conducted workshops on student-centered, problem-based learning. Since 2006, Karen has worked closely with the Exeter math curriculum, participating in summer editing work, and writing and developing teacher commentary for the entry-level (Math 1) materials.

Karen served as dean of academic affairs from 2012 to 2017, when she transitioned to assistant principal. 

Lassey brings to the role of assistant principal extensive knowledge of student performance as well as student discipline and crisis management. A passionate advocate for equity and inclusion at the Academy, she has served as an adviser to the Feminist Union and most recently as a member of the Gender Inclusion Task Force.

To complement her new role at Exeter, Lassey has begun a doctoral program in educational leadership at the University of Pennsylvania. 

She has coached field hockey, outdoor challenge, and outdoor fitness.

Beyond Exeter, she works as a volunteer with HAVEN, an area rape crisis center, and has been a host for the homeless through the Seacoast Interfaith Hospitality Network.