Lens (; ) is a municipality of Wallonia located in the province of Hainaut, Belgium.
In 2007 its population was 4042. The total area is 49.42 km<sup>2</sup> which gives a population density of 80 inhabitants per km<sup>2</sup>.
The municipality consists of the following districts: Bauffe, Cambron-Saint-Vincent, Lens, Lombise, and Montignies-lez-Lens.
It is located along the N56 road.