Pavel Kroupa (born 24 September 1963 in Jindřichův Hradec, Czechoslovakia) is a Czech-Australian astrophysicist and professor at the University of Bonn.
He acquired in 1983 his Abitur final exams in Göttingen and afterwards studied physics at The University of Western Australia in Perth.
In 1988 he won the Isaac Newton scholarship at the University of Cambridge and in 1992 the senior Rouse Ball research scholarship at Trinity College, Cambridge and attained a doctorate in England in 1992 with a dissertation on the distribution of low mass stars in the Milky Way.
In April 2004 he was appointed to the observatory of the University of Bonn, which is today a department of the Argelander Institute for Astronomy.
With this he explained in 2002 the observed heating or thickening with age of the disk of the Milky Way, and with Carsten Weidner he formulated the "IGIMF (integrated galactic initial mass function) theory".
In 1997 and in Heidelberg Kroupa, together with Ulrich Bastian, took the first precise measurement of the spatial movement of two extragalactic systems.