BEAUVAIS (the Casaromagus and Bellovac of antiquity), an arrondissement, department of Oise, in France, containing twelve cantons and 234 communes. Area 756 square miles. Pop. (in 1851) 101,983. The chief city, of the same name, is in a beautiful situation on the river Thérain, 21 miles N.W. of Paris. Pop. 12,508, employed in woollen, flax, cotton, earthenware, and carpet manufactures. The cathedral of Beauvais is one of the largest in France.