Ringgold County is a county in the U.S. state of Iowa. As of the 2010 census, the population was 5,131, making it the second-smallest population county in Iowa. The county seat is Mount Ayr. The county was founded in February 24, 1847 and named after Maj. Samuel Ringgold, a hero of the Battle of Palo Alto fought in May 1846, during the Mexican–American War. It is one of the 26 Iowa counties with a name that is unique across the nation.