Lake Piva (Montenegrin: Пивско језеро, romanized: Pivsko jezero) is a reservoir in Montenegro.

It is located in the northwest part of the country, in Plužine Municipality.

The surface of the lake is 12.5 km², the length is 45 km, and the maximum depth is 188 m.[citation needed] The elevation is 675 m above sea level.

[citation needed] The artificial lake is the result of the construction of Mratinje Dam on the Piva River.

[1] On the bottom of the lake there is the old town Plužine; Piva Monastery was also there, but it has been relocated.