Benton County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 221,339, making it the second-most populous county in Arkansas. The county seat is Bentonville. The county was formed on 30 September 1836 and was named after Thomas Hart Benton, a U.S. Senator from Missouri. In 2012, Benton County voters elected to make the county wet, or a non-alcohol prohibition location.