Dirk van Dalen (born 20 December 1932, Amsterdam) is a Dutch mathematician and historian of science.
Van Dalen studied mathematics and physics and astronomy at the University of Amsterdam. Inspired by the work of LEJ Brouwer and Arend Heyting, he received his Ph.D. in 1963 from the University of Amsterdam for the thesis Extension problems in intuitionistic plane Projective geometry. From 1964 to 1966 Van Dalen taught logic and mathematics at MIT, and later Oxford. From 1967 he was professor at the University of Utrecht. In 2003 Dirk van Dalen was awarded the Academy Medal 2003 of the Royal Dutch Academy of Sciences for bringing the works of Brouwer to international attention.