Dunajec River, river in southern Poland, rising in the Tatra Mountains near the Slovak border and flowing about 156 miles (251 km) northeast into the Vistula River.
The Dunajec River is dammed for hydropower at Rożnów, Czchów, and Czorsztyn. It was the scene of heavy fighting in World War I when the Germans broke through the Russian trenches. In March 1975 Czechoslovakia and Poland modified their border along the Dunajec to permit Poland to construct a dam in the Czorsztyn region, southeast of Kraków. Canoeing through the Pieniny gorge is a notable tourist activity.