Castelnau-le-Lez is a commune located in the Hérault department within the Occitanie region of southern France. It is positioned on the outskirts of Montpellier, situated approximately 3 km (1.8 mi) north of the city center.
The commune serves as a residential and geographic area adjacent to the larger urban hub of Montpellier, maintaining its own distinct administrative status within the regional framework of southern France.