Blegny (, before 2001: Blégny; ) is a municipality of Wallonia located in the Province of Liège, Belgium.
On January 1, 2006, Blegny had a total population of 12,799. The total area is 26.07 km<sup>2</sup> which gives a population density of 491 inhabitants per km<sup>2</sup>.
The municipality consists of the following districts: Barchon, Housse, Mortier, Saint-Remy, Saive, and Trembleur (town centre).