Columbus is a city in Columbia and Dodge counties in the U.S. state of Wisconsin. The population was 5,540 at the 2020 census, all of which resided in Columbia County. Columbus is located about 28 miles northeast of Madison on the Crawfish River. It is part of the Madison metropolitan area. Nearly all of the city is located within the town of Columbus in Columbia County, though a small portion lies within the town of Elba in Dodge County.