The Chiers (Luxembourgish: Kuer, German: Korn) is a river in Luxembourg, Belgium and France. It is a right tributary to the river Meuse. Its total length is about 130 km.
The source of the Chiers is near Differdange, in Luxembourg. The Chiers flows roughly in western direction.
It crosses the border with France, flows through Longwy and Longuyon (Meurthe-et-Moselle département) and forms the border with Belgium for a few km near Torgny (municipality of Rouvroy). It continues through France, along Montmédy (Meuse département) and Carignan (Ardennes département).
The Chiers flows into the river Meuse in Bazeilles, near Sedan.
Its main tributaries are the Loison and the Othain, along with smaller tributaries like the Aulnois.