Union County, Tennessee
County seat: Maynardville · Population 21,450 (2025) · 224 sq mi
Union County is the 66th most populous of Tennessee's 95 counties, with 21,450 people (2025 estimate). Its county seat is Maynardville. It is part of the East Tennessee region, one of the 3 Grand Divisions of Tennessee. The map shows its 3 cities and towns and the 5 neighboring counties.
Union County facts
- County seat
- Maynardville
- Population (2025 estimate)
- 21,450 +8.3% since 2020
- Land area
- 224 sq mi 86th largest of 95
- Water area
- 24 sq mi
- Population density
- 96 per sq mi
- Established
- 1850
- Same name
- One of 17 Union Counties in the US
- Largest city
- Maynardville 2,723
- Median household income
- $62,727
- Cities and towns
- 3
- ZIP codes
- 11
- Time zone
- Eastern
- FIPS code
- 47173
Cities and towns in Union County
Union County has 3 incorporated cities, towns and villages. Populations count the people living inside Union County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Maynardville (county seat) | City | 2,723 | |
| Plainview | City | 2,263 | |
| Luttrell | Town | 1,118 |
ZIP codes in Union County
11 ZIP codes reach into Union County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 37705 also Anderson County
- 37721 also Knox County
- 37754 also Anderson and Knox counties
- 37779 also Knox and Grainger counties
- 37807 also Knox County
- 37825 also Claiborne County
- 37848 also Grainger County
- 37866
- 37870 also Claiborne and Campbell counties
- 37888 also Grainger County
- 37938 also Knox and Anderson counties
Population of Union County, 2020–2025
Union County grew by 1,643 people (+8.3%) between April 2020 and July 2025: 478 more deaths than births and a net gain of 2,095 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 19,847 |
| 2021 | 20,020 |
| 2022 | 20,483 |
| 2023 | 20,760 |
| 2024 | 21,136 |
| 2025 | 21,450 |
Neighboring counties
- Claiborne County northeast · 33,229 people
- Campbell County northwest · 40,290 people
- Grainger County east · 25,739 people
- Knox County south · 511,453 people
- Anderson County southwest · 82,066 people
Printable Union County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (73 KB)
- PNG (2400 px) (81 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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