The Weil is 46.6-kilometre-long river in Hesse, Germany. It is a left tributary to the Lahn river and the town of Weilburg is located next to its mouth. The river flows exclusively through the Taunus mountain range with its source being located between the Kleiner Feldberg and Großer Feldberg mountains. It flows through Schmitten, Weilrod and Weilmünster. A hiking trail as well as a biking trail follow the course of the river.
