Knox County, Tennessee

Knox County, Tennessee
Location within the U.S. state of Tennessee
Coordinates: 35°59′N 83°56′W / 35.99°N 83.94°W / 35.99; -83.94
Country United States
State Tennessee
FoundedJune 15, 1792
Named afterHenry Knox
SeatKnoxville
Largest cityKnoxville
Government
 • MayorGlenn Jacobs (R)
Area
 • Total
526 sq mi (1,360 km2)
 • Land508 sq mi (1,320 km2)
 • Water18 sq mi (47 km2)  3.5%
Population
 (2020)
 • Total
478,971
 • Estimate 
(2024)
506,748
 • Density943/sq mi (364/km2)
Congressional district2nd
Websiteknoxcounty.org

Knox County is a county located in the U.S. state of Tennessee. The population was 506,748 as of a 2024 estimate, making it the third-most populous county in Tennessee. Its county seat is Knoxville, which is the third-most populous city in Tennessee. Knox County is included in the Knoxville metropolitan area. The county is located at the geographical center of the Great Valley of East Tennessee. Near the heart of the county is the origin of the Tennessee River, at the confluence of the Holston and French Broad rivers.