Mankato is a city in Blue Earth, Nicollet, and Le Sueur counties in the U.S. state of Minnesota. It is the county seat of Blue Earth County, Minnesota. The population was 44,488 at the 2020 census, making it the 21st-largest city in Minnesota, and the 4th-largest outside of the Minneapolis–Saint Paul metropolitan area. It is along a large bend of the Minnesota River at its confluence with the Blue Earth River. Mankato is across the Minnesota River from North Mankato.