Messancy (French pronunciation: [mεsɑ̃si]; German: Metzig; Luxembourgish: Miezeg; Walloon: Messanceye) is a municipality of Wallonia located in the province of Luxembourg, Belgium.

The municipality consists of the following districts: Habergy, Hondelange, Messancy, Sélange, and Wolkrange.

Other population centers include: Bébange, Buvange, Differt, Guelff, Longeau, and Turpange.

The European highway E411 from Brussels and Namur is double signed with the E25 until the exit in Weyler where it takes the N81 south.

It arrives from the provincial capital Arlon, passing the highway at the Weyler exit and continues south to Aubange and the French border near Longwy.