Clayton is the county seat of St. Louis County, Missouri, part of the Greater St. Louis metropolitan area. The population was 12,825 at the 2000 census. The city was organized in 1877 and is named after Ralph Clayton, who donated the land for the courthouse. Clayton has a highly rated public school system, possibly connected to its comparatively high real estate values. Clayton is one of St. Louis's wealthiest communities. Clayton is home to Washington University in St. Louis, Fontbonne University, and Concordia Seminary of the Lutheran Church - Missouri Synod. Clayton apartments for rent comparison page shows most up to date rent information on Clayton apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.