Liptovská Mara is a reservoir in northern Slovakia, on the Váh river near Liptovský Mikuláš, in the Liptov region. The dam is named after one of the inundated villages.
It was built in 1965-1975. The area of the reservoir is 22 km², max. depth is 45 m and the capacity is 360 mil. m³. During construction, nine villages were inundated and a major railway and road relocated. The main purpose of this dam is to prevent floods, although it also generates electricity.
Today, the dam is used as a recreational site. The reconstructed Celtic oppidum Havránok is situated on a hill above the dam.