Kansas City, abbreviated KC or KCMO, is the largest city in the U.S. state of Missouri by both population and area. It is located on the Missouri River at its confluence with the Kansas River, within Jackson, Clay, Platte and Cass counties. It is the 37th-most populous city in the United States and sixth-most populous city in the Midwest, with a population of 508,090 at the 2020 census. The Kansas City metropolitan area, which straddles the Missouri–Kansas state line, is the 31st-most populous metropolitan area in the nation, at 2.25 million residents.