Doubs, river, c.270 mi (435 km) long, rising in the Jura Mts., E France, and flowing northeast, forming part of the French-Swiss border, then looping into W Switzerland before turning back into France where it meanders southwest to empty into the Saône River. Lake of Brenets, a natural widening in the river, is a tourist center; at the northern end of the lake the river drops 88 ft (27 m). The Doubs is heavily canalized and passes through several industrial cities including Montbéliard and Besançon.

Doubs (dōō), department (1990 pop. 485,200), E France, in Franche-Comté, bordering on the Jura Mts. and on Switzerland. Besançon is the capital.