Morbihan, a maritime department of France, in Brittany, bordering on Cotes-du-Nord, Ille-et-Vilaine, Loire-Inferieure, Finistere, and the bay of Biscay; area, 2,625 sq. m.; pop. in 1872, 490,352 Its name is derived from a gulf on its shore, called Morbihan, or small sea. The coast is indented by numerous bays and harbors. Belle-Isle and several smaller islands off the coast belong to this department. The northern districts are hilly, but the southern are mainly composed of extensive and fertile plains. The principal river is the Vilaine, and the department is traversed by the Blavet and the Brest and Nantes canals. The sardine fishery gives employment to more than 3,000 men. The principal minerals are iron, tin, lead, slate, and salt. There are manufactures of linen, woollens, etc. Ship building is extensively carried on. The common cereals and flax and hemp are raised, and the department is celebrated for its cider. Much attention is paid to rearing bees, and wax and honey are among the principal exports.

The inhabitants of Morbihan are Bretons, and speak a dialect somewhat similar to that of the Cornish peasants in England. It is divided into the arrondissements of Lorient, Vannes, Pontivy or Napoleonville, and Ploermel. Capital, Vannes.