Dithmarschen is a district in Schleswig-Holstein, Germany. It is bounded by the districts of Nordfriesland, Schleswig-Flensburg, Rendsburg-Eckernförde, and Steinburg, by the state of Lower Saxony, and by the North Sea. From the 13th century up to 1559 Dithmarschen was an independent peasant republic within the Holy Roman Empire and a member of the Hanseatic League.

Schleswig-Holstein is the northernmost of the 16 states of Germany, comprising most of the historical Duchy of Holstein and the southern part of the former Duchy of Schleswig. Its capital city is Kiel; other notable cities are Lübeck and Flensburg. It covers an area of 15,763 km2 (6,086 sq mi), making it the 5th smallest German federal state by area.