Norrköping Municipality (Norrköpings kommun) is a municipality in Östergötland County in southeast Sweden. Its seat is located in the city of Norrköping, with some 90,000 inhabitants. By the time of the local government reform of 1971 the City of Norrköping was amalgamated with the rural municipality of Skärblacka forming a new municipality of unitary type. In 1974 Vikbolandet was added. The number of original local government units (as of 1863) which are in the present municipality is 26.