Warren County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 52,403. The county seat is Indianola.

Des Moines is the capital and most populous city in the U.S. state of Iowa. It is the county seat of Polk County with parts extending into Warren County. It was incorporated on September 22, 1851, as Fort Des Moines, which was shortened to "Des Moines" in 1857. It is located on, and named after, the Des Moines River, which likely was adapted from the early French name, Rivière des Moines, meaning "River of the Monks". The city's population was 214,133 as of the 2020 census. The six-county metropolitan area is ranked 81st in terms of population in the United States, with 709,466 residents according to the 2020 census by the United States Census Bureau, and is the largest metropolitan area fully located within the state.