The Montmorency River is a river in the Capitale-Nationale region of Quebec, Canada. It drains into the Saint Lawrence River, about 9 kilometers (6 mi) downstream from Quebec City. It is especially known for the impressive Montmorency Falls near its mouth.
It has an average flow of 35.6 m³/s. Typical average summer flow is about 25 m³/s, whereas during spring run-off, the river could swell anywhere from 130 to 650 m³/s. Above 770 m³/s is considered an exceptional flood condition, and the Montmorency experienced a record flow of 1100 m³/s in November 1966.