Upplands Väsby Municipality is a municipality in Stockholm County in east central Sweden, with a population of 38,963. Its seat is located in the town of Upplands Väsby.
The municipality was created in connection with the municipal reform of 1952, when the rural municipalities Ed, Fresta and Hammarby were amalgamated. It got its name from a settlement which had evolved around the railway station.
The name Väsby can be attested from the 13th century. The prefix "Upplands" came to be used by the post station in 1919 as a means of separating it from other Väsbys in the country. The municipality was then named "Upplands-Väsby" for a time, but the dash has now been removed.
Coordinates 59°31'16.896" N 17°54'18.435" E