Grand Morin

The Grand Morin (, literally Great Morin) is a 118 km long river in France, left tributary of the Marne. Its source is near the village of Lachy. Its course crosses the departments of Marne and Seine-et-Marne. It flows westwards through the towns of Esternay, La Ferté-Gaucher, Coulommiers and Crécy-la-Chapelle, finally flowing into the Marne in Esbly.

Its main tributary is the Aubetin.