St. Dennis is a census-designated place in Jefferson County, Kentucky, United States. The population was 9,177 at the 2000 census. In 2003, The area was annexed to the city of Louisville due to a merger between the city and Jefferson County's unincorporated communities. St. Dennis is now a neighborhood within the city limits of Louisville. St. Dennis apartments for rent comparison page shows most up to date rent information on St. Dennis apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.