Haderslev is a Danish town in the Region of Southern Denmark with a population of 22,182. It is the main town and the administrative seat of Haderslev Municipality and is situated in the eastern part of Southern Jutland. Haderslev is home of Sønderjyske, which is an association football team that plays in the Danish Superliga since 2008. The town is named after King Hader.

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 55,353 (2023). Its mayor is Mads Skau, representing the Venstre political party. Due to Kommunalreformen , Haderslev municipality was merged on January 1 of 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.