Korsholm is a municipality in Finland, located on the west coast of the country. Korsholm is situated in Ostrobothnia, along the Gulf of Bothnia. The population of Korsholm is approximately 20,000, while the sub-region has a population of approximately 111,000. It is the 55th most populous municipality in Finland. The town of Vaasa was founded in Korsholm parish in 1606 and today the municipality completely surrounds the city.