Pierre Pansu (born 13 July 1959) is a French mathematician and a member of the Arthur Besse group and a close collaborator of Mikhail Gromov. He is a professor at the Université Paris-Sud 11 and the École Normale Supérieure in Paris. His main research field is geometry. His contribution to mathematics is being celebrated by a double event (a conference and a workshop) co-organized for his 60th birthday by the Clay Mathematics Institute.