Lucas County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 8,634. The county seat is Chariton. The county was formed in 1846 and was named for Robert Lucas, a Governor of the Territory.

Chariton is a city in, and the county seat of, Lucas County, Iowa, United States. The population was 4,193 at the 2020 census. Lucas is the primary distribution center for and the former corporate headquarters of the Hy-Vee supermarket chain.