Oldham County is a county located in the north central part of the U.S. state and commonwealth of Kentucky. As of the 2020 census, the population was 67,607. Its county seat is La Grange. The county is named for Colonel William Oldham.

The Louisville metropolitan area is the 43rd largest metropolitan statistical area (MSA) in the United States. It had a population of 1,395,855 in 2020 according to the latest official census, and its principal city is Louisville, Kentucky.