The Danish minority in Southern Schleswig, Germany has existed since 1920, when the Schleswig Plebiscite split Schleswig into Northern Schleswig, which became a part of Denmark, and Southern Schleswig, which remained a part of Germany. Denmark has continued to support the minority financially. Danish schools and clubs have been run in the region, in Flensburg until 1926, and thereafter throughout the region.

The members of the minority have not always been the same people. In the 1920s, there were around 1,200 communists in the city of Flensburg, though the party declined in the pre-war years. During the Nazi dictatorship, the minority had an overall membership of 2,000. Historians believe that a large number of these were communists, many of whom were trying to avoid sending their children to schools directly controlled by the Nazis.

After World War II, many refugees were sent to Schleswig from areas that Germany had lost in the East. These composed as much as one third of the area's overall population. This division was a source of tension, and many people chose to join the Danish minority in hopes of joining the much more prosperous Denmark and to avoid having to take more refugees. At the end of 1946, the minority had thus reached a membership of 62,000.

However, the Danish government did not allow South Schleswig to join the kingdom, and in 1953 the so-called Programm Nord (Northern Programme) was set up by the Schleswig-Holstein state government to help the area economically. This caused the Danish minority to decline until the 1970s. Since then, the minority has slowly been gaining size, and these days numbers around 50,000, according to its major organizations, although no census has ever been made.