Jackson County was created by an act of the Tennessee General Assembly on November 6, 1801.

[4] In the 1790s, an Army outpost named Fort Blount was built 10 miles (16 km) west of Gainesboro on the Cumberland River, in what is now western Jackson County.

Williamsburg, a town developed around the fort, served as the Jackson County seat from 1807 to 1819.

[5] The county's early records were all lost in a disastrous courthouse fire on August 14, 1872.

[6] The 1970 Movie "I Walk The Line" starring Gregory Peck was filmed in Gainesboro and Jackson County.

As of the 2020 United States census, there were 11,617 people, 4,566 households, and 2,745 families residing in the county.

Only once up to 2008 did a Democrat lose the county – when Warren G. Harding carried Jackson County by ninety votes in his record popular-vote landslide of 1920, due to large increases in voter turnout for the isolationist cause Harding espoused.

[20] Whereas Al Gore (who grew up in nearby Smith County) won almost seventy percent of the vote in 2000, Barack Obama won by only thirty-nine votes in 2008, Mitt Romney became only the second Republican to carry the county in 2012 and Donald Trump four years later received a proportion of the vote for the GOP historically associated with Unionist East Tennessee counties.