De Fryske Marren is a municipality of Friesland in the northern Netherlands. It was established 1 January 2014 and consists of the former municipalities of Gaasterlân-Sleat, Lemsterland, Skarsterlân and parts of Boarnsterhim, all four of which were dissolved on the same day. The municipality is located in the province of Friesland, in the north of the Netherlands, and has a population of 51,430 and a combined area of 559.93 km².