Thun District is one of the 26 administrative districts in the canton of Bern, Switzerland. Its capital is the municipality of Thun. From 1 January 2010, the district lost its administrative power while being replaced by the new and enlarged Thun (administrative district), whose administrative centre remained Thun. Since 2010, it remains therefore a fully recognised district under the law and the Constitution (Art.3 al.2) of the Canton of Berne. The district has an area of 285 km2 and consists of 27 municipalities: