Doubs (French pronunciation: [du]; Arpitan: Dubs) is a department the Franche-Comté region of eastern France named after the Doubs River.

As early as the 13th century, inhabitants of the northern two-thirds of Doubs spoke the Franc-Comtois language, a dialect of Langue d'Oïl. Residents of the southern third of Doubs spoke a dialect of the Arpitan language. Both languages co-existed with French, the official language of law and commerce, and continued to be spoken frequently in rural areas into the 20th century. They are both still spoken today but not on a daily basis.

Doubs was important as a portal to Switzerland through the pass at Joux. Many famous people, including Mirabeau, Toussaint Louverture and Heinrich von Kleist, were imprisoned in the Château de Joux.

Doubs is one of the original 83 departments created during the French Revolution on 4 March 1790. It was created from part of the former province of Franche-Comté. The prefecture (capital) is Besançon.

In 1793, the republic of Mandeure was annexed by France and incorporated into the department. This district was passed between various territories and departments in the ensuing administrative reorganisations and wars, but was restored to Doubs in 1816 when the former principality of Montbéliard was also added to the department.