Spencer County is a county located in the U.S. state of Kentucky. As of the 2010 census, the population was 17,061. Its county seat is Taylorsville. The county was founded in 1824 and named for Spier Spencer. Spencer County is part of the Louisville/Jefferson County, KY–IN Metropolitan Statistical Area. Taylorsville Lake, located primarily within Spencer County, serves as a major economic resource for the area.