[6] The town was named for Revolutionary War figure Nancy Morgan Hart.

[8] It sits 4 miles (6 km) southwest of Lake Hartwell, which acquired its name from the city.

Hartwell is in the Piedmont region of Georgia, or the Upland South, and lies 30 miles (48 km) southeast of the foothills of the Appalachian Mountains at Toccoa.

U.S. Route 29 passes through the center of Hartwell, leading east 7 miles (11 km) to the South Carolina border at Hartwell Dam on the Savannah River, and southwest 12 miles (19 km) to Royston.

[4] As of the 2020 United States Census, there were 4,470 people, 1,592 households, and 1,013 families residing in the city.