Jefferson County, Kentucky
Jefferson County | |
|---|---|
Jefferson County Courthouse (now Louisville Metro Hall) in downtown Louisville | |
Location within the U.S. state of Kentucky | |
Kentucky's location within the U.S. | |
| Coordinates: 38°11′N 85°40′W / 38.19°N 85.66°W | |
| Country | United States |
| State | Kentucky |
| Founded | 1780 |
| Named after | Thomas Jefferson |
| Seat | Louisville |
| Largest city | Louisville |
| Area | |
• Total | 398 sq mi (1,030 km2) |
| • Land | 380 sq mi (1,000 km2) |
| • Water | 17 sq mi (40 km2) 4.3% |
| Population (2020) | |
• Total | 782,969 |
• Estimate (2024) | 793,881 |
| • Density | 2,000/sq mi (760/km2) |
| Time zone | UTC−5 (Eastern) |
| • Summer (DST) | UTC−4 (EDT) |
| Congressional districts | 3rd, 2nd |
| Website | louisvilleky |
Jefferson County is a county located in the north central portion of the U.S. state of Kentucky. As of the 2020 census, the population was 782,969. It is the most populous county in the commonwealth (with more than twice the population of second ranked Fayette County).
Since a city-county merger in 2003, the county's territory, population and government have been coextensive with the city of Louisville, which also serves as county seat. The administrative entity created by this merger is the Louisville/Jefferson County Metro Government, abbreviated to Louisville Metro.
Jefferson County is the anchor of the Louisville-Jefferson County, KY-IN Metropolitan Statistical Area, locally referred to as Kentuckiana.