Ripon is a city in Fond du Lac County, Wisconsin, United States. The population was 7,863 at the 2020 census. The city is surrounded by t…Ripon is a city in Fond du Lac County, Wisconsin, United States. The population was 7,863 at the 2020 census. The city is surrounded by the Town of Ripon. Ripon is home to the Little White Schoolhouse, the commonly recognized birthplace of the Republican Party.