Kortessem (Dutch pronunciation:[ˈkɔrtəsɛm]; Limburgish: Kotsoeve) is a municipality located in the Belgian province of Limburg near Hasselt. On January 1, 2006, Kortessem had a total population of 8,074. The total area is 33.90 km2 which gives a population density of 238 inhabitants per km2.
The municipality consists of the following sub-municipalities: Kortessem, Guigoven, Vliermaal, Vliermaalroot, and Wintershoven.
Up until its destruction by a storm in 2009, Kortessem was the home of the Onzelievehereboom: a 1200-year-old oak.