Kortessem (; ) is a former 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 km<sup>2</sup> which gives a population density of 238 inhabitants per km<sup>2</sup>.
The former municipality consisted 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.
Since 16 May 2014 Herman Van Rompuy is an honorary citizen.
Kortessem has been part of Hasselt since January 1, 2025.