Jan Theodoor Gerard Overbeek (Groningen, January 30, 1911 – February 19, 2007) was a Dutch professor of physical chemistry at the Utrecht University. Overbeek was born in Groningen. Overbeek's family moved to Rotterdam in 1913 and to Breda in 1925. Overbeek went to study chemistry (from 1928-1933) at the Utrecht University. He spent a year in military service and then worked for two years in Belgium. First year he worked with Jacques Errera at the Université libre de Bruxelles, after that a year with Arend Joan Rutgers at Ghent University.