Izak (Ieke) Moerdijk (Dutch: [ˈikə ˈmurdɛik]; born 23 January 1958) is a Dutch mathematician who in 2012 won the prestigious Spinoza prize.
Moerdijk obtained his PhD at the University of Amsterdam in 1985. From 1988 to 2011 he was professor at Utrecht University. Since then he has been professor of Mathematics at the Mathematisch Instituut of the Radboud University Nijmegen. He is the author of several influential books.
- Mac Lane, Saunders; Moerdijk, Ieke (1994) Sheaves in geometry and logic. A first introduction to topos theory. Corrected reprint of the 1992 edition. Universitext. Springer-Verlag, New York, 1994.
- Moerdijk, I.; Mrčun, J. (2003) Introduction to foliations and Lie groupoids. Cambridge Studies in Advanced Mathematics, 91. Cambridge University Press, Cambridge.
- Moerdijk, Ieke; Reyes, Gonzalo E. (1991) Models for smooth infinitesimal analysis. Springer-Verlag, New York.
- Joyal, A.; Moerdijk, I. (1995) Algebraic set theory. London Mathematical Society Lecture Note Series, 220. Cambridge University Press, Cambridge.
- Ieke Moerdijk, "Classifying spaces and classifying topoi", Lecture Notes in Mathematics 1616, Springer 1995. vi+94 pp. ISBN 3-540-60319-0