Madison is a city located primarily in Madison County, near the northern border of the U.S. state of Alabama. Madison extends west into neighboring Limestone County. The city is included in the Huntsville Metropolitan Area, the second-largest in the state, and is also included in the merged Huntsville-Decatur Combined Statistical Area. As of the 2010 census, the population of the city was 42,938. Madison is bordered by Huntsville on all sides.