Appleton is the county seat of Outagamie County, Wisconsin, United States, with small portions extending into Calumet and Winnebago c…Appleton is the county seat of Outagamie County, Wisconsin, United States, with small portions extending into Calumet and Winnebago counties. Located on the Fox River, it lies 30 miles southwest of Green Bay and 100 miles north of Milwaukee. Appleton had a population of 75,644 at the 2020 census, making it the sixth-most populous city in Wisconsin. It is the principal city of the Appleton metropolitan statistical area, which had 243,147 residents in 2020 and is part of the broader Fox Cities region.