| Le Lez | |
| Pushpin Map: | France#France Occitanie |
| Source1 Location: | Saint-Clément-de-Rivière |
| Source1 Coordinates: | 43.7181°N 3.8442°W |
| Mouth Location: | Mediterranean Sea (Palavas-les-Flots) |
| Mouth Coordinates: | 43.5258°N 3.9339°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | France |
| Length: | 29.6km (18.4miles) |
The Lez (in French pronounced as /lɛz/; Occitan (post 1500);: Les) is a 29.6km (18.4miles) river in the Hérault department in southern France. It is the main river of the city of Montpellier. The river has its source in the forest 5 km north of Saint-Clément-de-Rivière and it flows into the Mediterranean Sea at Palavas-les-Flots after first passing between two large lagoons and intersecting with the Canal du Rhône à Sète. Its longest tributary is the Mosson. The small fish Cottus petiti is endemic to a short stretch of the Lez.