Molenbeek-Saint-Jean, also known as Sint-Jans-Molenbeek or simply Molenbeek, is one of the 19 municipalities located within the Brussels-Capital Region of Belgium. Situated in the western part of the region, it shares borders with the City of Brussels to the east, which is separated from the municipality by the Brussels–Charleroi Canal. It also borders the municipalities of Anderlecht, Berchem-Sainte-Agathe, Dilbeek, Jette, and Koekelberg.
The municipality takes its name from the Molenbeek brook, which flows through the area. In accordance with regional regulations, Molenbeek-Saint-Jean is officially bilingual, recognizing both French and Dutch as official languages.