The Westerwald is a mountain chain in Germany. It is located on the junction of the states (Bundesländer) of Rhineland-Palatinate, North Rhine-Westphalia and Hesse.

The mountains are bounded by four river valleys: the Rhine in the west, the Sieg in the north, the Dill in the east, and the Lahn in the south.

The highest peak is the Fuchskaute with 656 meters. 40 percent of the Westerwald's about 1000 km² are covered with woods.