Ringgold County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 4,663, making it the Iowa county with the second-smallest population. The county seat is Mount Ayr. The county is 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.