Sénart, community in the départements of Seine-et-Marne and Essonne, Île-de-France région, north-central France. An agglomeration of eight villages southeast of Paris (Cesson, Combs-la-Ville, Tigery, Vert-Saint-Denis, Nandy, Mossy Cramayel, Réau, and Savigny-le-Temple), Sénart is one of the villes nouvelles (new towns) that were developed outside the capital beginning in 1965. Growth of Sénart has been relatively modest, partly as a result of over-optimistic projections made at the time of its launch. Nonetheless, considerable residential development has occurred. The community’s economy is based on light industry and services.