Saint-Clair-sur-Epte (French pronunciation: [sɛ̃ klɛːʁ syʁ ɛpt] ⓘ; literally 'Saint-Clair on Epte') is a commune in the Val-d'Oise department in Île-de-France in northern France.

It is situated on the river Epte, 10 km southwest of Gisors.

The treaty of Saint-Clair-sur-Epte in 911 established Rollo, a Norse warlord and Viking leader, as the first Duke of Normandy.

Henry I of England seized the castle of Saint-Clair-sur-Epte in 1118.

This Val-d'Oise geographical article is a stub.