The Lenne is a tributary of the river Ruhr in the Sauerland hills, western Germany.

It has caused flooding in recent years.

[2] Having its source on top of the Kahler Asten near Winterberg in an intermittent spring at an elevation of 2,687 ft (819 m), the Lenne ends after a course of 129 km flowing into the Ruhr river near the city of Hagen.

With an average discharge of 25 m³/s near its mouth, it is the main tributary of the Ruhr.

This article related to a river in North Rhine-Westphalia is a stub.