Sioux Falls is the most populous city in the U.S. state of South Dakota and the 145th-most populous city in the United States. It is the county seat of Minnehaha County and also extends into Lincoln County to the south. It is the 47th-fastest-growing city in the United States and the fastest-growing metro area in South Dakota, with a population increase of 22% between 2000 and 2010.
As of 2018, Sioux Falls had an estimated population of 183,200. The metropolitan population of 251,854 accounts for 29% of South Dakota's population.