There are 95 counties in the U.S. State of Tennessee. As of 2021, Shelby County was both Tennessee's most populous county, with 924,454 residents, and the largest county in area, covering an area of 755 sq mi (1,955 km2). The least populous county was Pickett County (5,079) and the smallest in area was Trousdale County, covering 114 sq mi (295 km2). As of the same year, Davidson County, in which the capital Nashville is located, covers 502 sq mi (1,300 km2) with a population of 703,953. The population of the state of Tennessee as of the 2021 census estimate was 6,975,218 in an area of 42,169 sq mi (109,217 km2). The oldest county is Washington County, founded in 1777. The most recently formed county is Chester County (1879).