Crookston is a city in the U.S. state of Minnesota. It is the county seat of Polk County. The population was 7,482 at the 2020 census. It is part …Crookston is a city in the U.S. state of Minnesota. It is the county seat of Polk County. The population was 7,482 at the 2020 census. It is part of the "Grand Forks, ND-MN Metropolitan Statistical Area" or "Greater Grand Forks".