Most of the city of Cedar Hill is in Dallas County, but a small southern section of the city spills over into Ellis County. All of the very small southern section of the city is Ellis County and has few roads in the southern section. Cedar Hill is a suburb of Dallas and is part of the Best Southwest area, which includes the nearby cities of DeSoto, Duncanville, and Lancaster. Cedar Hill is a city in Dallas and Ellis Counties in the U.S. state of Texas. It is located approximately sixteen miles southwest of downtown Dallas and is situated along the eastern shore of Joe Pool Lake and Cedar Hill State Park. The population was 32,093 at the 2000 census. A 2009 North Central Texas Council of Governments (NCTCOG) estimate placed the population at 45,600.