Kansas City, Missouri is the most populous city in Missouri and largest by area. As of the 2020 census, the city had a population of 508,090, making it the 37th most-populous city in the United States. It is the urban central city of the Kansas City metropolitan area, which straddles the Missouri–Kansas state line and has a population of 2,392,035. Most of the city lies within Jackson County, with portions spilling into Clay, Cass, and Platte counties.