Jan Denef (born 4 September 1951) is a Belgian mathematician.
He is an Emeritus Professor of Mathematics at the Katholieke Universiteit Leuven (KU Leuven).Denef obtained his Ph.D.
from KU Leuven in 1975 with a thesis on Hilbert's tenth problem; his advisors were Louis Philippe Bouckaert and Willem Kuijk.He is a specialist of model theory, number theory and algebraic geometry.
He is well known for his early work on Hilbert's tenth problem and for developing the theory of motivic integration in a series of papers with François Loeser.