Hartsville is a town in Trousdale County, Tennessee, United States. It is the county seat of Trousdale County, with which it shares a consolidated city-county government. The population of Hartsville was 7,870 as of 2010.
Hartsville now shares with Trousdale County a consolidated city-county government by virtue of a referendum which passed in Trousdale County in 2000. Despite the city-county government, under Tennessee law, Hartsville is also considered to be a distinct municipality. Trousdale County High School is located here, as well a Tennessee Colleges of Applied Technology campus operated by the Tennessee Board of Regents. Trousdale County is one of two counties in Tennessee to have legalized parimutuel betting on horse racing, but no group has ever stepped forward to build a racetrack. Hartsville is located slightly north of the Cumberland River and is approximately fifty miles northeast of Nashville.
In 1977, the Tennessee Valley Authority began construction on the Hartsville Nuclear Plant, but cancelled the project in 1984 after spending nearly $2 billion. The plant's unused cooling tower dominates the view south from State Route 25 between Smith County and Trousdale County. In 2016, Corrections Corporation of America (since renamed CoreCivic) opened the Trousdale Turner Correctional Center, a medium-security prison, in between Smith County and Trousdale County.