Fond du Lac County is a county in the U.S. state of Wisconsin. As of the 2020 census, the population was 104,154. Its county seat is Fond du Lac. The county was created in the Wisconsin Territory in 1836 and later organized in 1844. Fond du Lac is French for "bottom of the lake", given so because of the county's location at the southern shore of Lake Winnebago. Fond du Lac County comprises the Fond du Lac, Wisconsin Metropolitan Statistical Area. The Holyland region is in northeastern Fond du Lac County.

Wisconsin's 6th congressional district is a congressional district of the United States House of Representatives in eastern Wisconsin. It is based in the rural, suburban and exurban communities between Madison, Milwaukee, and Green Bay. It also includes the village of River Hills in far northern Milwaukee County. The district is currently represented by Glenn Grothman (R-Glenbeaulah) who took office in January 2015.