Duncanville is a city in Dallas County, Texas. Duncanville's population was 36,081 at the 2000 census. Duncanville is a suburb of Dallas and is part of the Best Southwest area, which includes Duncanville, Cedar Hill, DeSoto, and Lancaster. Duncanville apartments for rent comparison page shows most up to date rent information on Duncanville apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.