Ray County is a county located in the U.S. state of Missouri. As of 2010, the population was 23,494. Its county seat is Richmond. Ray County is part of the Kansas City Metropolitan Area. The county was organized on 16 November 1820 (effective 1 January 1821 and named for John Ray, a Missouri state legislator. According to the 2000 census, the county has a total area of 573.57 square miles, of which 569.47 square miles (or 99.29%) is land and 4.11 square miles (or 0.72%) is water.