Huntsville is a city in mountainous Madison County, Arkansas, United States. The population was 2,046 at the 2010 census. The city is the county seat of Madison County. During the American Civil War it was the site of what became known as the Huntsville Massacre. Huntsville was incorporated in 1925. Huntsville is part of the Fayetteville–Springdale–Rogers, AR-MO Metropolitan Statistical Area.