Watonwan County is a county in the U.S. state of Minnesota. As of the 2020 census, the population was 11,253. Its county seat is St. James. In 1849, the new territorial legislature of the recently organized Minnesota Territory authorized the creation of nine large counties across the Territory. Four years later in 1853, one of those original counties of Dakota, ha…Watonwan County is a county in the U.S. state of Minnesota. As of the 2020 census, the population was 11,253. Its county seat is St. James. In 1849, the new territorial legislature of the recently organized Minnesota Territory authorized the creation of nine large counties across the Territory. Four years later in 1853, one of those original counties of Dakota, had a large area separated and partitioned off to create Blue Earth County. Less than only two years later, by 1855, the western part of Blue Earth was then partitioned to create Brown County. Again, after five years on February 25, 1860, the southern part of Brown was partitioned to create this county of Watanwan, with the town of Madelia as the original designated County Seat. The county was named for its eponymous river,, whose name reflects the Dakota native word "watanwan," meaning "fish bait" or "plenty of fish." The word first appears in the modern written record on an 1843 map of the area so naming the river.