Sioux City is a city in Woodbury and Plymouth counties in the U.S. state of Iowa. The population was 85,797 at the 2020 census, and was estimated at 86,875 in 2024, making it the fourth-most populous

The Sioux City metropolitan statistical area, as defined by the United States Census Bureau, is an area consisting of four counties in three states – Iowa, Nebraska, and South Dakota, anchored by the