Madison County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 15,717. The county seat is Huntsville. The county was formed on September 30, 1836, and named for James Madison, fourth President of the United States.Madison County is part of the Fayetteville - Springdale - Rogers, AR-MO Metropolitan Statistical Area.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (0.3%) is water.Adjacent countiesCarroll County (north)Newton County (east)Johnson County (southeast)Franklin County (south)Crawford County (southwest)Washington County (west)Benton County (northwest)