Ligny-en-Barrois (liɲi ɑ̃ baʁwa) is a commune in the Meuse department in Grand Est in north-eastern France. The town is in the arrondissement of Bar-le-Duc, beside the canal that links the rivers Rhine and Marne, fifteen kilometres to the south east of Bar-le-Duc: it is the administrative seat of the canton Ligny-en-Barrois. The population comprises 4,018 inhabitants (2019) and the area of Ligny is 32.26 km2. The inhabitants are called in French Linéens. A principal employer is the French Evobus motor bus assembly plant. Ligny is also the home town of the Essilor company which specialises in ophthalmic lens production.