Lauwersmeer (Dutch pronunciation: [ˌlʌu.ərsˈmeːr]) is a man-made lake in the north of the Netherlands, on the border of the provinces of Groningen and Friesland.

During the flood the mouth of the river Lauwers disappeared, and its tributaries the Reitdiep, the Dokkumerdiep, and the Ee flowed directly into the new bay.

However, parts of it were empoldered piecemeal, slowly reducing it from a large two-forked estuary to the nearly square inlet seen on recent maps.

In Leeuwarden a large gathering was organised to show the government that local people did not agree with the decision.

New flora and fauna appeared as the Lauwerszee gradually became a freshwater lake, and to protect this new and young nature area, it was decided (12 November 2003) to designate the Lauwersmeer as a national park.