Marc Henneaux (b. 1955, Brussels) is a Belgian physicist and professor at the Universite Libre de Bruxelles (ULB). He studied physics at the ULB and obtained his PhD in 1980. Presently he serves as Director of the Service de Physique Théorique et Mathématique at the ULB and as the chair of the International Solvay Institutes for Physics and Chemistry (founded by Ernest Solvay). In 2000 he was awarded the Francqui Prize for Exact Sciences.