Nacka Municipality is a municipality in Stockholm County in east-central Sweden. Its seat is located at Nacka. The municipality is situated just east of the capital Stockholm and the western parts are considered a suburban part of the city of Stockholm.

Stockholm is the capital and most populous city of Sweden as well as the largest urban area in the Nordic countries. Approximately 1 million people live in the municipality, with 1.6 million in the urban area, and 2.4 million in the metropolitan area. The city stretches across fourteen islands where Lake Mälaren flows into the Baltic Sea. Outside the city to the east, and along the coast, is the island chain of the Stockholm archipelago. The area has been settled since the Stone Age, in the 6th millennium BC, and was founded as a city in 1252 by Swedish statesman Birger Jarl. The city serves as the county seat of Stockholm County.