The Lipno Dam (Czech: Vodní nádrž Lipno 'Lipno Dam') is a lake in the southwest of the Czech Republic, part of the Vltava Cascade (Czech: Vltavská kaskáda) and forms its fourth oldest and highest level. It is located on the border with Austria in the Bohemian Forest National Park and Landscape Protection Area (Czech: Národní park a chráněná krajinná oblast Šumava) in the Okres Český Krumlov (Krumau District), only a small offshoot of the lake in the northwest lies in the Okres Prachatice (Prachacyjno District), in the southwest a very small part on Austrian territory (Rohrbach District, Upper Austria).
The reservoir was created in 1959 after a dam with a power plant was built in the Vltava valley between 1952 and 1959. This measure was intended to protect the region, especially the downstream towns of České Budějovice (Bohemian Budweis) and Prague, from flooding. Even then, the lake was nicknamed Jihočeské moře (South Bohemian Sea) or Šumavské moře (Bohemian Forest Sea).