The Mratinje Dam (Montenegrin: Брана Мратиње, romanized: Brana Mratinje) is a concrete arch dam in the canyon of the Piva River in Montenegro.

The dam is 220 metres (720 ft) high, one of the highest in Europe.

820,000 cubic metres (1,070,000 cu yd) of concrete and 5,000 tonnes of steel were built into the dam.

[2] The hydroelectric power station at Mratinje is capable of producing 860 gigawatt-hours per annum.

The location of the 16th century Piva Monastery was flooded by the lake, so while the dam was built, the monastery was broken into pieces and moved to a higher ground, 3.5 km away.