Originally the commune was called Évry-sur-Seine (meaning "Évry upon Seine"). The name "Évry" comes from the Gallic name Eburacon or Eburiacos, meaning "land of Eburos" (a Gallic patronym), perhaps the leader of a Gallic tribe in the area before the conquest of Gaul by the Romans. After the conquest, the name was corrupted into Latin Apriacum, then Medieval Latin Avriacum, and later Evriacum.
In 1881 the name of the commune was changed into Évry-Petit-Bourg at the request of entrepreneur Paul Decauville, owner of Ateliers de Petit-Bourg, a large boiler works located in Évry and at the time the largest employer in the area. The factory owed its name to the hamlet of Petit-Bourg (one of the three hamlets on the territory of Évry) where it was built.
On 29 June 1965 the name of the commune was shortened into "Évry" only. Évry had just been chosen to become a "" of the suburbs of Paris, destined to host tens of thousands of suburbanites, and so the name "Petit-Bourg" (literally meaning "little borough, small town" in modern French, although etymologists think that this name was in fact the corruption of an old Gallic word with a totally different meaning) was deemed too old fashioned and improper for the new large suburban city of Évry to be built.