Bornholm is a Danish island in the Baltic Sea. It also refers to the Bornholm Regional Municipality, a municipality (Danish, kommune) covering the entire island.
Bornholm is located to the east of Denmark, the south of Sweden, and the north of Poland. The main industries on the island include fishing, pottery using locally worked clay, clockmaking and dairy farming. Tourism is important during the summer.
The small islands Ertholmene are located 18 km to the north-east of Bornholm.
Strategically located in the Baltic Bornholm has been a bone of contention usually ruled by Denmark, but also by Lübeck and Sweden. The castle ruin Hammershus on the northwestern tip of the island gives testimony to its importance.