Houston County is a county located in the U.S. state of Minnesota. As of 2020, the population was 18,843. Its county seat is Caledonia. The United States Census Bureau's La Crosse Metropolitan Statistical Area includes all of Houston County (as well as La Crosse County, Wisconsin, to the east).
According to the U.S. Census Bureau, the county has a total area of 569 square miles (1,473 km˛), of which 552 square miles is land and 7 square miles is water.