Dudelange (Luxembourgish: Diddeleng, German: Düdelingen) is a commune with city status in southern Luxembourg. It is the fourth-most populous commune, with over 18,300 inhabitants. Dudelange is situated close to the border to France.
As of 2006, the town of Dudelange, which lies in the centre of the commune, has a population of 17,320, making it Luxembourg's third-most populous town. The commune also includes the smaller town of Budersberg, to the north-west. The Mont St. Jean, close to Budersberg, hosts the ruins of a medieval castle.
Dudelange is an important industrial town that grew out of the three villages and a steel mill in 1900. The D in the name of the ARBED steel company, later merged into ArcelorMittal, stood for 'Dudelange.' It is also the site of Dudelange Radio Tower, which is an FM radio and television transmitter.
One of Dudelange's most notable citizens was the Impressionist painter Dominique Lang (1874–1919).
Furthermore Dudelange is home to the most successful Luxembourg football club in recent history. F91 Dudelange won nine national titles in the period 2000 to 2011.