​ARMENTIÈRES, a town of northern France, in the department of Nord, on the Lys, 13 m. W.N.W. of Lille on the Northern railway from that city to Dunkirk. Pop. (1906) 25,408. The chief building is the hôtel de ville with a 17th-century belfry. There are communal colleges for girls and boys, a board of trade-arbitrators, a chamber of commerce and a national technical school. The town is an important centre for the spinning and weaving of flax and cotton; bleaching, dyeing and the manufacture of machinery are among the other industries. Its industrial prosperity dates from the middle ages, when, however, woollen, not cotton, goods were the staple product.