For the adjacent former town, see Menasha (town), Wisconsin. Menasha is a city in Calumet and Winnebago counties in the U.S. state of Wisconsin. The population was 17,353 at the 2010 census. Of this, 15,144 were in Winnebago County, and 2,209 were in Calumet County. The city is located mostly in Winnebago County; only a small portion is in the Town of Harrison in Calumet County.