Isselburg is a town in the district of Borken, in North Rhine-Westphalia, Germany. It is located on the river Issel, near the border of the Netherlands, and approximately 10 km west of Bocholt. The largest villages are Anholt, Isselburg, and Werth. Smaller communities include Vehlingen, Herzebocholt and Heelden.
Isselburg had a population of 10,636 at the end of 2019. It uses postcode 46419 today.