Mäntsälä is a municipality of Finland. It is located in the province of Southern Finland and is part of the Uusimaa region.
Mäntsälä lies about 60 km north of Helsinki, the capital of Finland. During the last few years, the population of Mäntsälä has been one of the most rapidly increasing in Finland. Mäntsälä is considered to have been founded in 1585, when the community's first church was built.