Trüebsee (lit.: dull lake, Germanized: Trübsee) is an Alpine lake (1,764 m (5,787 ft)) and an Alpine pasture in the upper part of the extensive municipality of Wolfenschiessen in the Swisscanton of Nidwalden. The lake lies at the foot of the Titlis on the Alpine pasture called Ober Trüebsee (or often just incorrectly shortened to Trüebsee) and above the village resort of Engelberg. It can be reached from the village by cable car, or via the Pfaffenwand alpine walking path.
The lake is a hydroelectric reservoir, providing water to the underground power station Trübsee (opened in 1968) near Engelberg town, before flowing into the lake Eugenisee.
View of the lake, seen from the cable car up to the Titlis