Jefferson County is an exurban county located in the U.S. state of Tennessee. As of the 2020 census, the population was 54,683. Its county seat is Dandridge. Jefferson County is part of the Morristown Metropolitan Statistical Area with neighboring Grainger and Hamblen counties. The county, along with the Morristown MSA, is included in the Knoxville-Morristown-Sevierville Combined Statistical Area.

Jefferson County was established on June 11, 1792, by William Blount, Governor of the Southwest Territory. It had been a part of Caswell County during the State of Franklin period (1784–1789). Its county seat, Dandridge, was settled in 1783.

On the eve of the Civil War, Jefferson County, like most other counties in mountainous East Tennessee, was opposed to secession. In Tennessee's Ordinance of Secession referendum on June 8, 1861, Jefferson County voters rejected secession by a margin of 1,987 to 603. A railroad bridge at Strawberry Plains was among those targeted by the East Tennessee bridge-burning conspiracy in November 1861. This led to internal conflict in the area throughout the war, with men from the county enlisting in both of the rival armies.

On October 2, 2013, on I-40 in Jefferson County near the I-40 and I-81 split, a multi-vehicle collision involving a church bus, a tractor-trailer, and a SUV occurred at mile marker 423. Tennessee Highway Patrol officials discovered that the church bus had blown a tire, leading it to merge into oncoming traffic, clipping the SUV and colliding with the semi-truck, causing it to burst into flames. The accident resulted in 8 fatalities and 14 injuries.

United States presidential election results for Jefferson County, Tennessee

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	21,068	81.61%	4,503	17.44%	244	0.95%
2020	18,651	78.98%	4,654	19.71%	311	1.32%
2016	14,776	77.47%	3,494	18.32%	802	4.21%
2012	13,038	74.25%	4,232	24.10%	289	1.65%
2008	13,092	70.65%	5,178	27.94%	262	1.41%
2004	11,625	67.53%	5,469	31.77%	121	0.70%
2000	8,657	61.45%	5,226	37.10%	204	1.45%
1996	6,446	53.03%	4,688	38.57%	1,021	8.40%
1992	6,184	50.02%	4,740	38.34%	1,438	11.63%
1988	6,832	67.85%	3,168	31.46%	69	0.69%
1984	7,721	70.35%	3,185	29.02%	69	0.63%
1980	6,944	66.82%	3,180	30.60%	268	2.58%
1976	5,459	57.23%	3,995	41.89%	84	0.88%
1972	5,925	80.26%	1,357	18.38%	100	1.35%
1968	5,494	67.11%	1,494	18.25%	1,199	14.65%
1964	4,923	65.44%	2,600	34.56%	0	0.00%
1960	6,141	78.79%	1,620	20.79%	33	0.42%
1956	4,870	77.63%	1,338	21.33%	65	1.04%
1952	4,622	78.87%	1,228	20.96%	10	0.17%
1948	2,979	74.12%	900	22.39%	140	3.48%
1944	3,159	76.25%	966	23.32%	18	0.43%
1940	1,921	63.95%	1,062	35.35%	21	0.70%
1936	2,356	68.33%	1,079	31.29%	13	0.38%
1932	2,275	68.59%	975	29.39%	67	2.02%
1928	2,582	85.55%	436	14.45%	0	0.00%
1924	2,699	78.39%	712	20.68%	32	0.93%
1920	3,583	81.58%	741	16.87%	68	1.55%
1916	1,648	75.84%	520	23.93%	5	0.23%
1912	540	26.96%	514	25.66%	949	47.38%

According to the U.S. Census Bureau, the county has a total area of 314 square miles (810 km), of which 274 square miles (710 km) is land and 40 square miles (100 km) (13%) is water. The county is affected by two artificial lakes: Douglas Lake, created by the damming of the French Broad River in the south, and Cherokee Lake, created by the damming of the Holston River in the north.

• Hamblen County (northeast)
• Cocke County (southeast)
• Sevier County (south)
• Knox County (west)
• Grainger County (north)

• Henderson Island Refuge

• I-40
• I-81
• US 11E
• US 25E
• US 25W
• US 70
• US 411
• SR 9
• SR 32
• SR 34
• SR 35
• SR 66
• SR 92

• SR 113
• SR 139
• SR 341
• SR 363

Historical population

Census	Pop.	Note	%±
1810	7,309		—
1820	8,953		22.5%
1830	11,801		31.8%
1840	12,076		2.3%
1850	13,204		9.3%
1860	16,043		21.5%
1870	19,476		21.4%
1880	15,846		−18.6%
1890	16,478		4.0%
1900	18,590		12.8%
1910	17,755		−4.5%
1920	17,677		−0.4%
1930	17,914		1.3%
1940	18,621		3.9%
1950	19,667		5.6%
1960	21,493		9.3%
1970	24,940		16.0%
1980	31,284		25.4%
1990	33,016		5.5%
2000	44,294		34.2%
2010	51,407		16.1%
2020	54,683		6.4%
2023 (est.)	57,838		5.8%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2014

Jefferson County racial composition

Race	Number	Percentage
White (non-Hispanic)	48,975	89.56%
Black or African American (non-Hispanic)	787	1.44%
Native American	159	0.29%
Asian	257	0.47%
Pacific Islander	20	0.04%
Other/Mixed	2,093	3.83%
Hispanic or Latino	2,392	4.37%

As of the 2020 United States census, there were 54,683 people, 20,154 households, and 13,998 families residing in the county.

As of the census of 2000, there were 44,294 people, 17,155 households, and 12,608 families residing in the county. The population density was 162 people per square mile (63 people/km). There were 19,319 housing units at an average density of 71 units per square mile (27/km). The racial makeup of the county was 95.66% White, 2.32% Black or African American, 0.31% Native American, 0.27% Asian, 0.04% Pacific Islander, 0.63% from other races, and 0.77% from two or more races. 1.33% of the population were Hispanic or Latino of any race.

There were 17,155 households, out of which 31.00% had children under the age of 18 living with them, 59.90% were married couples living together, 9.80% had a female householder with no husband present, and 26.50% were non-families. 22.50% of all households were made up of individuals, and 8.20% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 2.89.

In the county, the population was spread out, with 22.90% under the age of 18, 10.60% from 18 to 24, 29.10% from 25 to 44, 24.50% from 45 to 64, and 12.90% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 97.50 males. For every 100 females age 18 and over, there were 94.00 males. However, the last statistic is somewhat misleading because of female longevity, and if adults 18-65 were considered, the numbers would be very close to equal.

The median income for a household in the county was $32,824, and the median income for a family was $38,537. Males had a median income of $29,123 versus $20,269 for females. The per capita income for the county was $16,841. About 9.60% of families and 13.40% of the population were below the poverty line, including 16.90% of those under age 18 and 12.60% of those age 65 or over.

According to a data profile produced by the Tennessee Department of Economic and Community Development in 2023, the top employers in the county are:

#	Employer	# of Employees
1	Old Dominion Freight Line	1,100
2	Jefferson County Board of Education	1,100
3	Bush Brothers and Company	500
4	Nyrstar	450
5	Carson–Newman University	404
6	Oshkosh Corporation	325
7	Jefferson Memorial Hospital	305
8	Jefferson County Government	300
9	Walmart (Jefferson City)	300
10	Ball MetalPack	159

K-12 public education in the county is conducted by Jefferson County Public Schools.

• Baneberry
• Jefferson City
• Morristown (partial, mostly in Hamblen)

• Dandridge (county seat)
• New Market
• White Pine (small portion in Hamblen)

• Strawberry Plains (partial, portions in Knox and Sevier)

• Belmont
• Chestnut Hill
• Shady Grove
• Talbott (partial)

• National Register of Historic Places listings in Jefferson County, Tennessee

• Official website
• Convention and Visitors Bureau
• Jefferson County Schools
• Jefferson County Chamber of Commerce

36°03′N 83°27′W / 36.05°N 83.45°W / 36.05; -83.45