Jefferson County is located in the north central portion of the U.S. Commonwealth of Kentucky. As of the 2010 census, the population was 741,096. 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.