Stefaan Vaes (born February 29th, 1976 in Herentals, Belgium) is a Belgian mathematician. Vaes studied mathematics at the KU Leuven with a diploma in 1998 and a PhD in 2001 with thesis advisor Alfons Van Daele and thesis Locally Compact Quantum Groups. As a postdoc he was from 1998 to 2002 at KU Leuven and from 1998 to 2002 in Paris, where he did research for CNRS. In 2002 he began part-time teaching at the KU Leuven, where he became an associate professor in 2006 and a full professor in 2009. His research deals with Von Neumann algebras and quantum groups. His doctoral students include .