Lake Millstatt is a lake in Carinthia, Austria.
It is situated at 588 metres above the Adriatic (1,929 ft), north of the Drava Valley within the Gurktal Alps (Nock Mountains) range of the Central Eastern Alps, near the town of Spittal an der Drau. With a surface area of 13.3 km2 (5.1 sq mi) Lake Millstatt is the second largest lake of Carinthia (after Lake Wörth), though with a depth of 142 m (466 ft) the most voluminous by far.
Its steep shore gives the lake a fjord-like character. The Millstätter Alpe mountains in the north up to 2,100 m (6,900 ft) protect it from cold winds, so the water temperature can reach 25 °C (77 °F) in summer. The narrow and long surface stretches over 12 km (7.5 mi) from east to west. In the south the wooded Hochgosch plateau, with a breadth of 2 km (1.2 mi) and an elevation of 876 m (2,874 ft), divides the lake from the parallel Drava Valley.
Fishery, especially for trout, had been a source of food and work for residents since ancient times. Today sport fishing and angling is quite common not only for trout but also for several genera of carps, for wels catfish, northern pike, zander, perch and the European eel.