Grâce-Hollogne (French pronunciation: ​[ɡʁas ɔlɔɲ]; Walloon: Gråce-Hologne) is a municipality of Belgium. It lies in the country's Walloon Region and Liège Province. The municipality is effectively a part of the greater Liège conurbation, separated from Liège city centre by the municipality of Saint-Nicolas. Included within its boundaries is Liège Airport. On 1 January 2006 Grâce-Hollogne had a total population of 21,753. The total area is 34.24 km2, which gives a population density of approximately 635 inhabitants per km2.