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.

U.S. Route 275 (US 275) is a north–south United States highway that is a branch of US 75. It originally terminated at US 75 in Council Bluffs, Iowa. The highway's northern terminus is in O'Neill, Nebraska, at an intersection with U.S. Highway 20 and U.S. Highway 281. Its southern terminus is near Rock Port, Missouri, at an intersection with U.S. Highway 136.