Michel Paul Lazard (5 December 1924 – 15 September 1987) was a French mathematician who worked on the theory of Lie groups in the context of p-adic analysis.
His work took on a life of its own in the hands of Daniel Quillen in the late 20th century. Quillen's discovery, that a ring Lazard used to classify formal group laws was isomorphic to an important ring in topology, led to the subject of chromatic homotopy theory. Lazard's self-contained treatise on one-dimensional formal groups also gave rise to the field of p-divisible groups. His major contributions were:
Chevalley, Claude (2005). Classification des groupes algébriques semi-simples [The classification of semisimple algebraic groups, with the collaboration of P. Cartier, A. Grothendieck and M. Lazard]. Collected works (in French). Vol. 3. Springer-Verlag. ISBN3-540-23031-9. MR2124841. New edition of Séminaire C. Chevalley, 1956–1958: Classification des groupes de Lie algébriques, Secrétariat Math., 11 rue Pierre Curie, Paris, 1958.