| Settlement Type: | Town |
| Nordborg | |
| Pushpin Map: | Denmark#Denmark Region of Southern Denmark |
| Pushpin Map Caption: | Location in Denmark |
| Coordinates: | 55.0589°N 9.7481°W |
| Subdivision Type: | Country |
| Subdivision Name: | Denmark |
| Subdivision Type1: | Region |
| Subdivision Name1: | Southern Denmark |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Sønderborg |
| Area Urban Km2: | 5.24 |
| Population As Of: | 2024 |
| Population Urban: | 5729 |
| Population Density Urban Km2: | auto |
| Population Blank1 Title: | Gender [1] |
| Population Blank1: | 2856 males and 2873 females |
| Timezone1: | CET |
| Utc Offset1: | +1 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +2 |
| Postal Code Type: | Postal code |
| Postal Code: | DK-6430 Nordborg |
Nordborg (de|Norburg), is a town with a population of 5,729 (1 January 2024),[2] which was the seat of the former Nordborg municipality (Danish, kommune) in Sønderborg Municipality, Region of Southern Denmark on the northwest half of the island of Als off the east coast of the Jutland peninsula in south Denmark.
Within the town is Nordborg Castle, a historic castle whose premises are currently used as a boarding school.
The town has been greatly influenced by the presence of Danfoss, a global producer of components for refrigeration and airconditioning, heating and motion control applications, headquartered in the town and founded in 1933.
The former Nordborg Municipality covered an area of 125 km2, and had a total population of 13,956 (2005). Its last mayor was Jan Prokopek Jensen, a member of the Social Democrats (Socialdemokraterne) political party.
The municipality was created in 1970 as the result of a Danish: kommunalreform ("Municipality Reform") that merged a number of existing parishes:
Over the years the presence of Danfoss has made the former Nordborg Municipality, the site of one of the largest industrial workplaces in Denmark. In later years, the municipality saw the rise of another major industrial company, Linak, a global producer of electric linear actuator systems.
On 1 January 2007 Nordborg Municipality ceased to exist as the result of Kommunalreformen ("The Municipality Reform" of 2007). It was merged with Augustenborg, Broager, Gråsten, Sundeved, Sydals, and Sønderborg municipalities to form the new Sønderborg Municipality. This created a municipality with an area of 499 km2 and a total population of 49,886 (2005).