Heidelberg is a university town in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. In the 2016 census, its population was 159,914, of which roughly a quarter consisted of students.

Located about 78 km (48 mi) south of Frankfurt, Heidelberg is the fifth-largest city in Baden-Württemberg. Heidelberg is part of the densely populated Rhine-Neckar Metropolitan Region.