Schleswig-Holstein is the northernmost of the sixteen states of Germany, comprising most of the two historical duchies of Schleswig and Holstein. Its capital city is Kiel; other notable cities are Lübeck, Flensburg and Neumünster.

Schleswig-Holstein borders Denmark (Region Syddanmark) to the north, the North Sea to the west, the Baltic Sea to the east, and the German states of Lower Saxony, Hamburg, and Mecklenburg-Vorpommern to the south.

The former English name was Sleswick-Holsatia, the Danish name is Slesvig-Holsten, the Low German name is Sleswig-Holsteen, and the North Frisian name is Slaswik-Holstiinj. Historically, the name can also refer to a larger region, containing both present-day Schleswig-Holstein and the former South Jutland County (Northern Schleswig) in Denmark.

Culture
Schleswig-Holstein combines Danish and German aspects of culture. The castles and manors in the countryside are the best example for this tradition; some dishes like Rote Grütze are also shared.

The most important festivals are the Schleswig-Holstein Musik Festival, an annual classic music festival all over the state, and the Nordische Filmtage, an annual film festival for movies from Scandinavian countries, held in Lübeck.

The annual Wacken Open Air festival is considered to be the largest heavy metal rock festival in the world.

The state's most important museum of cultural history is in Schloss Gottorf in Schleswig.

The old city of Lübeck is a world heritage site.