The Heuneburg is a prehistoric Celtic hillfort by the river Danube in Hundersingen near Herbertingen, between Ulm and Sigmaringen, Baden-Württemberg, in the south of Germany, close to the modern borders with Switzerland and Austria. It is considered to be one of the most important early Celtic centres in Central Europe, particularly during the Iron Age Hallstatt culture period. Apart from the fortified citadel, there are extensive remains of settlements and burial areas spanning several centuries.

The Celts or Celtic peoples were a collection of Indo-European peoples in Europe and Anatolia, identified by their use of Celtic languages and other cultural similarities. Major Celtic groups included the Gauls; the Celtiberians and Gallaeci of Iberia; the Britons, Picts, and Gaels of Britain and Ireland; the Boii; and the Galatians. The relation between ethnicity, language and culture in the Celtic world is unclear and debated; for example over the ways in which the Iron Age people of Britain and Ireland should be called Celts. In current scholarship, 'Celt' primarily refers to 'speakers of Celtic languages' rather than to a single ethnic group.