Lemay is a census-designated place in St. Louis County, Missouri, United States. The population was 17,215 at the 2000 census. Lemay was named after Francois Lemai, who operated the ferry across the Meramec River in the early nineteenth century. Lemay apartments for rent comparison page shows most up to date rent information on Lemay apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.