Trosa Municipality
Trosa Municipality is in Södermanland County in southeast Sweden. The seat is the town of Trosa, and the municipality also includes Vagnhärad, Västerljung, Stensund, and Sund. It was created in 1992 when Nyköping Municipality was split into three parts. It borders Nyköping Municipality, Gnesta Municipality, and to the north Södertälje Municipality in Stockholm County.
The municipality covers about 665 square kilometers in total, with around 210 km2 of land and 455 km2 of water. As of 30 June 2025, about 14,929 people live there, giving a population density of roughly 71 inhabitants per square kilometer. It lies in the province of Södermanland and uses the municipal code 0488.
Trosa is close to Stockholm, which makes it a popular destination for tourists and visitors. In the summer, the population increases significantly as people from the Stockholm area stay in the municipality’s holiday homes. The well-equipped harbor and the archipelago attract many pleasure boats from Sweden and other Baltic Sea countries.
This page was last edited on 3 February 2026, at 21:03 (CET).