Jamestown is a city in, and the county seat of, Fentress County, Tennessee, United States. The population of the city was 1,959 at the 2010 census.
Jamestown was established in 1823 as a county seat for Fentress County. It was incorporated as a city in 1837. Both Fentress County and Jamestown are named for prominent local politician James Fentress (1763–1843), who made the appeal for the new county to be carved out of Overton and Morgan counties.
Jamestown was built upon the site of a semi-permanent Cherokee village, which probably made use of the many natural rock shelters in the area. Before the founding of Jamestown, the area was known as "Sand Springs" for the many bubbling springs located within the city. The last remaining spring is located in the Mark Twain City Park, just northeast of the county courthouse. This spring provided water to the family of John M. Clemens, father of noted author Samuel L. Clemens (Mark Twain), before they moved to Missouri. John Clemens served as the first circuit court clerk.