North Mankato is a city in Nicollet and Blue Earth counties in the State of Minnesota. The population was 14,275 at the 2020 census. Most of …North Mankato is a city in Nicollet and Blue Earth counties in the State of Minnesota. The population was 14,275 at the 2020 census. Most of North Mankato is in Nicollet County, but a small part extends into Blue Earth County. It is neighbored to the south across the Minnesota River by Mankato. The two cities have a combined population of 58,763. North Mankato is the smaller of the two principal cities of the Mankato-North Mankato Metropolitan Statistical Area.