Jean-Louis Verdier (French: [vɛʁdje]; 2 February 1935 – 25 August 1989) was a French mathematician who worked, under the guidance of his doctoral advisor Alexander Grothendieck, on derived categories and Verdier duality. He was a close collaborator of Grothendieck, notably contributing to SGA 4 his theory of and anticipating the later development of by Michael Artin and Barry Mazur, following a suggestion he attributed to Pierre Cartier. 's related theory of was later taken up by Eric Friedlander in his definition of the . Verdier later worked on the theory of integrable systems.