Gaasterlân-Sleat (population: 10,621) is a municipality in the northern Netherlands, in the province of Friesland. The municipality covers an area of 209.29 km² (of which 101.54 km² water).
The municipality of Gaasterlân-Sleat consists the following towns, villages and townships: Bakhuizen, Balk, Elahuizen, Harich, Kolderwolde, Mirns, Nijemirdum, Oudega, Oudemirdum, Rijs, Ruigahuizen, Sloten, Sondel, Wijckel.