Union County, Pennsylvania
County seat: Lewisburg · Population 42,313 (2025) · 316 sq mi
Union County is the 50th most populous of Pennsylvania's 67 counties, with 42,313 people (2025 estimate). Its county seat is Lewisburg. It is part of the District 3 region, one of the 11 PennDOT engineering districts. The map shows its 4 cities and towns and the 6 neighboring counties.
Union County facts
- County seat
- Lewisburg
- Population (2025 estimate)
- 42,313 −0.9% since 2020
- Land area
- 316 sq mi 64th largest of 67
- Water area
- 2 sq mi
- Population density
- 134 per sq mi
- Established
- 1813
- Same name
- One of 17 Union Counties in the US
- Named after
- United States country located primarily in North America
- Largest city
- East Buffalo 8,084
- Median household income
- $76,404
- Cities and towns
- 4 plus 7 CDPs
- ZIP codes
- 14
- Time zone
- Eastern
- FIPS code
- 42119
Cities and towns in Union County
Union County has 4 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 |
|---|---|---|---|
| Lewisburg (county seat) | Borough | 5,226 | |
| Mifflinburg | Borough | 3,436 | |
| New Berlin | Borough | 771 | |
| Hartleton | Borough | 245 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Linntown | 1,764 | |
| Winfield | 909 | |
| West Milton | 804 | |
| New Columbia | 766 | |
| Vicksburg | 289 | |
| Laurelton | 258 | |
| Allenwood | 246 |
ZIP codes in Union County
14 ZIP codes reach into Union County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 17810 also Lycoming County
- 17829
- 17835
- 17837
- 17844
- 17845
- 17855
- 17856
- 17870 also Snyder County
- 17880
- 17885
- 17886
- 17887
- 17889 also Snyder County
Population of Union County, 2020–2025
Union County shrank by 367 people (−0.9%) between April 2020 and July 2025: 268 more deaths than births and a net loss of 158 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 42,659 |
| 2021 | 42,480 |
| 2022 | 42,713 |
| 2023 | 42,185 |
| 2024 | 42,641 |
| 2025 | 42,313 |
Neighboring counties
- Snyder County south · 39,655 people
- Northumberland County southeast · 89,920 people
- Centre County west · 157,393 people
- Lycoming County north · 112,587 people
- Mifflin County southwest · 46,127 people
- Clinton County northwest · 37,870 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) (98 KB)
- PNG (2400 px) (86 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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