Bilzen (Dutch pronunciation: [ˈbɪlzə(n)] ⓘ) is a city and a municipality located in the Belgian province of Limburg.

Cities in Bilzen's neighbourhood are all within a distance of some 10 to 15 kilometers: to its north, Genk; to its east, Maastricht (Netherlands); to its south Tongeren; and to its north-west, Diepenbeek.

In its time Jazz Bilzen was the most important Belgian festival.

Artists that performed there were, among many others, Humble Pie, The Moody Blues, Deep Purple, Black Sabbath, Humble Pie, The Kinks, The Troggs, Procol Harum, Golden Earring, Rod Stewart, Status Quo, Lou Reed, Aerosmith, AC/DC, The Cure, Toots Thielemans, Keith Jarrett and John McLaughlin.

For over 300 years, Bilzen was part of the County of Loon (French: comté de Looz).