Reutlingen, nicknamed "The Gate to the Swabian Alb" (German: "Das Tor zur Schwäbischen Alb"), is a Landkreis (district) in the middle of Baden-Württemberg, Germany.
The former free imperial city (until 1802) reached the limit of 100,000 residents in 1989.
Reutlingen district's neighboring districts are (from north clockwise) Esslingen, Göppingen, Alb-Donau, Biberach, Sigmaringen, Zollernalbkreis, Tübingen and Böblingen.
The district dates back to the Oberamt Reutlingen, which was created in 1803 when the previously free imperial city Reutlingen became part of Württemberg.
A few municipalities from the districts Tübingen, Saulgau, Sigmaringen and Nürtingen were also added.