Blegny is a municipality of Wallonia located in the Province of Liège, Belgium. On January 1, 2006, Blegny had a total population of 12,79…Blegny 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 km² which gives a population density of 491 inhabitants per km².