Wattrelos (French pronunciation: ​[wa.tʁə.lo]; archaic Dutch: Waterlos) is a commune in the Northern department in the Nord-Pas de Calais region in northern France. It is located on the border with Belgium, northeast of the city of Lille. It the fifth-largest component of the metropolitan Urban Community of Lille Métropole. Wattrelos borders the communes of Roubaix, Tourcoing and Leers in France and the communes of Moeskroen and Steenput in Belgium.