Montluçon (French: [mɔ̃.ly.sɔ̃] is a commune in central France on the Cher river. It is the largest commune in the Allier department, although the department's préfecture is located in the smaller town of Moulins. Its inhabitants are known as Montluçonnais. The town is in the traditional province of Bourbonnais and was part of the mediaeval duchy of Bourbon.