Wattrelos is a commune situated in the Nord department within the Hauts-de-France region of northern France. It is positioned on the border with Belgium, located to the northeast of the city of Lille.
The municipality serves as the fifth-largest component of the Métropole Européenne de Lille. Wattrelos shares borders with several neighboring communes, including Roubaix and Tourcoing in France, as well as Mouscron and Estaimpuis in Belgium.