Liptovská Mara (in Slovak pronounced as /ˈliptɔwskaː ˈmara/) 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, thirteen 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.