Thomas Kappeler was a Swiss mathematician and professor at the University of Zurich.
Kappeler's main research was in global analysis, partial differential equations and dynamical systems in infinite dimensions.
Kappeler co-founded the Zurich Graduate School in Mathematics, a joint doctoral program of the Mathematics departments of ETH Zurich and University of Zurich. He also actively supported young kids with talent in mathematics. He was the co-leader of the children's math club Junior Euler Society.