Mercer County, Pennsylvania
County seat: Mercer · Population 107,860 (2025) · 673 sq mi
Mercer County is the 30th most populous of Pennsylvania's 67 counties, with 107,860 people (2025 estimate). Its county seat is Mercer. It is part of the District 1 region, one of the 11 PennDOT engineering districts. The map shows its 16 cities and towns and the 6 neighboring counties.
Mercer County facts
- County seat
- Mercer
- Population (2025 estimate)
- 107,860 −2.5% since 2020
- Land area
- 673 sq mi 33rd largest of 67
- Water area
- 10 sq mi
- Population density
- 160 per sq mi
- Established
- 1800
- Same name
- One of 8 Mercer Counties in the US
- Named after
- Hugh Mercer Jacobite and General in the American Revolutionary War
- Largest city
- Hermitage 16,308
- Median household income
- $59,976
- Cities and towns
- 16 plus 2 CDPs
- ZIP codes
- 28
- Time zone
- Eastern
- FIPS code
- 42085
Cities and towns in Mercer County
Mercer County has 16 incorporated cities, towns and villages. Populations count the people living inside Mercer County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Hermitage | City | 16,308 | |
| Sharon | City | 12,648 | |
| Grove City | Borough | 7,694 | |
| Greenville | Borough | 5,406 | |
| Farrell | City | 4,110 | |
| Sharpsville | Borough | 4,095 | |
| Mercer (county seat) | Borough | 1,905 | |
| Stoneboro | Borough | 922 | |
| West Middlesex | Borough | 772 | |
| Sandy Lake | Borough | 624 | |
| Clark | Borough | 558 | |
| Jamestown | Borough | 556 | |
| Fredonia | Borough | 417 | |
| New Lebanon | Borough | 195 | |
| Jackson Center | Borough | 189 | |
| Sheakleyville | Borough | 145 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Reynolds Heights | 1,845 | |
| Lake Latonka | 651 |
ZIP codes in Mercer County
28 ZIP codes reach into Mercer County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 16057 also Butler and Lawrence counties
- 16110 also Crawford County
- 16113
- 16114
- 16121
- 16124
- 16125 also Crawford County
- 16127 also Venango, Lawrence and Butler counties
- 16130
- 16133
- 16134 also Crawford County
- 16137
- 16142 also Lawrence County
- 16143 also Lawrence County
- 16145
- 16146
- 16148
- 16150
- 16151
- 16153 also Venango County
- 16154
- 16156 also Lawrence County
- 16159 also Lawrence County
- 16161
- 16311 also Venango County
- 16314 also Crawford and Venango counties
- 16342 also Venango County
- 16362 also Venango County
Population of Mercer County, 2020–2025
Mercer County shrank by 2,801 people (−2.5%) between April 2020 and July 2025: 3,187 more deaths than births and a net gain of 393 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 110,553 |
| 2021 | 110,002 |
| 2022 | 109,142 |
| 2023 | 108,556 |
| 2024 | 108,238 |
| 2025 | 107,860 |
Neighboring counties
- Crawford County north · 81,792 people
- Trumbull County, Ohio west · 198,972 people
- Lawrence County south · 83,911 people
- Venango County east · 49,346 people
- Butler County southeast · 200,169 people
- Mahoning County, Ohio southwest · 224,706 people
Printable Mercer 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) (113 KB)
- PNG (2400 px) (91 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.
Back to the Pennsylvania county map with all 67 counties. Found an error? Tell us.