Saint Paul is the capital city of the U.S. state of Minnesota and the county seat of Ramsey County. As of the 2020 census, the city had a popula…Saint Paul is the capital city of the U.S. state of Minnesota and the county seat of Ramsey County. As of the 2020 census, the city had a population of 311,527, making it the second-most populous city in Minnesota and the 63rd-most populous in the United States. Together with neighboring Minneapolis, the two cities form the core of the Twin Cities metropolitan area, the third most populous in the Midwest with around 3.7 million residents.