Appleton is a city in and the county seat of Outagamie County, Wisconsin, United States. A small portion of the city also extends into Calumet and Winnebago counties. It is situated on the Fox River, 30 miles southwest of Green Bay and 100 miles north of Milwaukee. As of the 2020 census, it had a population of 75,644, making it the sixth-most populous city in Wisconsin.