Haderslev Municipality is a town and municipality on the east coast of the Jutland peninsula in the Region of Southern Denmark. It includes 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 55,438 (2024). Its mayor is Mads Skau, representing the Venstre political party. Following the Kommunalreformen , Haderslev municipality was merged on 1 January that year with the former municipalities of Gram and Vojens, as well as Bjerning, Hjerndrup, and Fjelstrup parishes of Christiansfeld Municipality and Bevtoft parish of Nørre Rangstrup Municipality.