Lahn-Dill is a Kreis (district) in the west of Hesse, Germany. Neighboring districts are Siegen-Wittgenstein, Marburg-Biedenkopf, Gießen, Wetteraukreis, Hochtaunuskreis, Limburg-Weilburg, Westerwaldkreis.
In 1977 the district Gießen was merged with the districts Wetzlar and Dillkreis to the new Lahn-Dill-Kreis. However this big district wasn’t popular, so in 1979 Giessen was split from it.
The main rivers of the district are the Lahn and the Dill, which also gave it the name. It is mountain landscape with the Westerwald in the west, the Taunus in the south, the Lahn-Dill-Bergland in the east and the Rothaargebirge of the Sauerland in the north. The highest elevation with 671 m is near Rittershausen (part of Dietzhölztal), the lowest with 135 is in the Lahn valley in Biskirchen (part of the city Leun).