Bilzen

|picture-legend = Alden Biesen Castle |map-legend = Location of Bilzen in Limburg |postal-codes = 3740, 3742, 3746 |telephone-area = 089 Bilzen () is a former municipality and city located in the Belgian province of Limburg.

In 2021, Bilzen had a total population of 32,536. The total area is 75.90 km2 which gives a population density of 426 inhabitants per km2.

Bilzen consists of the city of Bilzen and the following villages: Beverst, Eigenbilzen, , , , , , , , Rijkhoven, , and . In 1977 they all became part of the municipality Bilzen because of the fusion of municipalities.

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

From 1965 to 1981 Bilzen hosted Jazz Bilzen, an annual multi-day open air jazz and rock festival. In its time Jazz Bilzen was the most important Belgian festival. Artists that performed, among many others, included: 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. From the 1980s onwards, the festival was superseded by Torhout-Werchter, which has now become Rock Werchter.