Haderslev (German: Hadersleben) is a town and municipality on the east coast of the Jutland peninsula in south Denmark. Also included is the island of Årø as well as several other smaller islands in the Little Belt. The municipality covers 701.98 km² (271 sq mi) and has a population of 56,414 (2008). Its mayor is Jens Christian Gjesing, representing the Social Democratic Party. It belongs to Region of Southern Denmark.