Polk County was created in 1853 by the state legislature from the northern part of St. Croix County. The new county was named after James Polk who was President of the United States from 1845 to 1849 and signed the legislation that granted statehood to Wisconsin. Thus Polk County is one of the presidential counties of Wisconsin.
In 1856 Burnett County was formed from the northern part of Polk County and in 1859 the eastern part of the county was split off to form Dallas County which was eventually renamed Barron County. There were some border adjustments with both Burnett and Barron County but the boundaries of Polk County have remained the same since 1870 or so.
The Village of Balsam Lake is the county seat. The area was originally inhabited by a band of Chippewa Native Americans. The settlement was organized as a town in 1870 and it was named after the lake that is within the town borders.
The Polk County Justice Center is located at 1005 West Main Street in Balsam Lake. The old Polk County courthouse is now the Polk County Museum and is located 120 Main Street in Balsam Lake. The old courthouse was built in 1899 and was the courthouse until 1975. The building was added to the National Register of Historic Places in 1982.