Decize, a town of central France, in the department of Nièvre, on an island in the Loire, 24 m. S.E. of Nevers by the Paris-Lyon railway. Pop. (1906) 3813. The most important of its buildings is the church of Saint Aré, which dates in part from the 11th and 12th centuries; there are also ruins of a castle of the counts of Nevers. The town has a statue of Guy Coquille, the lawyer and historian, who was born there in 1523. Decize is situated at the starting-point of the Nivernais canal. The coal mine of La Machine, which belongs to the Schneider Company of Le Creusot, lies four miles to the north. The industries of Decize and its suburbs on both banks of the Loire include the working of gypsum and lime, and the manufacture of ceramic products and glass. Trade is in horses from the Morvan, cattle, coal, iron, wood and stone.
Under the name of Decetia the place is mentioned by Julius Caesar as a stronghold of the Aedui, and in 52 B.C. was the scene of a meeting of the senate held by him to settle the leadership of the tribe and to reply to his demand for aid against Vercingetorix. In later times it belonged to the counts of Nevers, from whom it obtained a charter of franchise in 1226.