Österåker Municipality (Österåkers kommun, ˈœ̂sːtɛrˌoːkɛʂ kʊˈmʉːn) is a municipality in Stockholm County in east central Sweden. Its seat is located in the town of Åkersberga, with a population of 26,727 (2005).
From 1974 to 1982 Österåker was part of Vaxholm Municipality.
Its location by the Stockholm archipelago, in the Roslagen area, attracts both people who settles here, often commuting to Stockholm, and visiting tourists. Österåker boasts several golf courses, many possibilities for canoeing, horse riding, fishing and other nature activities.
Österåker also has a historical significance, with at least three notable castles from the 17th and 18th centuries, with histories tracing even further back. Sweden's once largest quartz mine, the Härsbacka mine, lays within the municipality.
Like many other municipalities making up Metropolitan Stockholm, Österåker has a significant outward-commuting mainly to Stockholm, with some 13,000 commuters.
Of the 800 islan