Madison County is a county in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 35,585. Its county seat is Madison and its largest city is Norfolk. Madison County was likely named for Madison, Wisconsin, which is where many of the county’s residents came from; the city was named for James Madison, fourth President of the United States. Madison County is part of the Norfolk, NE Micropolitan Statistical Area.