Cergy-Pontoise (French pronunciation: [sɛʁʒi pɔ̃twɑz]) is a new town and an agglomeration community in France, in the Val-d'Oise and Yvelines departments, northwest of Paris on the river Oise.

As of 2022[update], the communauté d'agglomération Cergy-Pontoise consists of thirteen communes:[2][3] Except Maurecourt, which is in the Yvelines department, all communes are part of the Val-d'Oise department.

Since the establishment of the new agglomeration, the population has quadrupled over forty years.

The old city was to be integrated in a much larger unit, whose center would be Cergy, at the time not more than a village.

From 1965, the establishment of the new city was to be done in several stages: Bus services are provided by the Stivo (formerly StAN).