| Düne | |
| Map: | Germany |
| Location: | German Bight |
| Coordinates: | 54.1847°N 7.9122°W |
| Archipelago: | Heligoland |
| Area Km2: | 0.7 |
| Country: | Germany |
| Country Admin Divisions Title: | State |
| Country Admin Divisions: | Schleswig-Holstein |
| Country Admin Divisions Title 1: | District |
| Country Admin Divisions 1: | Pinneberg district |
| Country Admin Divisions Title 2: | Municipality |
| Country Admin Divisions 2: | Heligoland |
| Population: | unpopulated |
| Website: | helgoland.de |
Düne (Danish: Dynen, North Frisian: de Halem) is one of two islands in the German Bight that form the Archipelago of Heligoland, the other being Heligoland proper.
The small island of Düne is part of the German State of Schleswig-Holstein. Situated 1miles to the east of the main island Heligoland, Düne is part of the Heligoland protected natural area. The island measures 0.78miles in length and 0.53miles in width. The island is separated from Heligoland proper by the Rede strait.
Until the 17th century, Düne was connected to Heligoland. On New Year's Eve 1721 a big storm surge separated the dunes from Heligoland. Therefore, the island that arose was called Düne (English: Dune). In 1935 the size of the island was 10ha. In 1940 the Nazi government increased the size of the island to 40ha. This increase was for use as a military airfield. The Heligoland Airfield is still used today and has three runways, of which the longest is 480m (1,580feet).