Mons-lez-Liege (Walloon: Mont-dlé-Lidje) is a section of the Belgian municipality of Flémalle located in the Walloon Region, in the province of Liège. The town was also known under the name of Mons-Crotteux until 1977.
It was a separate municipality before the merging of municipalities in 1977. The hamlet of Cahottes was part of Horion-Hozémont until then, but was transferred to Mons-lez-Liège.
It is the birthplace of Louis Antoine, in 1846. He founded the Antoinism in Jemeppe-sur-Meuse in 1910.
Coordinates: 50°37′N 05°27′E / 50.617°N 5.450°E