[8] 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 prison became a hot spot for COVID-19 cases in the COVID-19 pandemic, giving the county the highest incidence rate in the U.S. in May 2020, with 1 in 7 residents known to be infected with coronavirus.

[10] The first Euro-American settlers arrived in what is now Hartsville in 1797, when the family of James Hart settled along the west bank of the West Fork of Goose Creek, and the family of Charles Donoho settled along the creek's east bank.

[11] Trousdale County is noted for having the 4th most TSSAA high school football championships, behind Alcoa, Maryville, and Brentwood Academy.

Trousdale County High School won state championships in 1972, 1990, 1993, 1997, 1998, 2005, 2008, 2009, and 2013, and was runner-up in 1973, 1974, 1975, and 2018.

[14] The town's business district is situated along the West Fork of Goose Creek, which flows into Trousdale County from the hills to the north and empties into the Old Hickory Lake impoundment of the Cumberland River several miles to the south.

A large hill rises immediately to the west of the business district and overlooks the entire eastern half of the county.

Hartsville lies at the junction of State Route 25, which connects the town with Carthage to the southeast and Sumner County to the west, and State Route 141, which connects Hartsville with Lebanon to the south and Macon County to the north.

According to the United States Census Bureau, the town has a total area of 3.6 square miles (9.3 km2) in 2000, all land.