Irondale is a city in St. Francois County, Missouri, United States. The population was 445 at the 2010 census. Irondale is located at 37°50′…Irondale is a city in St. Francois County, Missouri, United States. The population was 445 at the 2010 census. Irondale is located at 37°50′7″N 90°40′21″W / 37.83528°N 90.67250°W. According to the United States Census Bureau, the city has a total area of 0.54 square miles, of which 0.53 square miles is land and 0.01 square miles is water.