Mesen (Dutch: [ˈmeːsə(n)] ⓘ; French: Messines [mɛsin], historically used in English) is a city and municipality located in the Belgian province of West Flanders.
The municipality comprises only one main settlement, the town of Mesen proper.
An exclave to the west of the main territory is surrounded by the municipalities of Heuvelland and Comines-Warneton.
Villages neighbouring the municipality: Mesen is the smallest city in Belgium.
In 1062, Adela, wife of Baldwin the Pius, count of Flanders, translated the bones of Saint Sidronius from Rome to Messines.