The Duchy of Schleswig (; ; Low German: Sleswig; North Frisian: Slaswik) was a principality in Southern Jutland (Sønderjylland) covering the area about 60 km north and 70 km south of the current border between Germany and Denmark; the territory has been divided between the two countries since 1920, with Northern Schleswig in Denmark and Southern Schleswig in Germany. The region is also called Sleswick in English.

The Duchy of Schleswig (; ; Low German: Sleswig; North Frisian: Slaswik) was a principality in Southern Jutland (Sønderjylland) covering the area about 60 km north and 70 km south of the current border between Germany and Denmark; the territory has been divided between the two countries since 1920, with Northern Schleswig in Denmark and Southern Schleswig in Germany. The region is also called Sleswick in English.