Columbia County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 24,552. The county seat is Magnolia. The county was formed on December 17, 1852, and was named for Christopher Columbus. It was an alcohol prohibition or dry county. However, the voters of Columbia County voted on November 4, 2014 to make it legal to buy, sell, and manufacture alcohol within the county. The county will no longer be dry.