Suffolk County, Massachusetts
County seat: Boston · Population 791,891 (2025) · 58 sq mi
Suffolk County is the 4th most populous of Massachusetts's 14 counties, with 791,891 people (2025 estimate). Its county seat is Boston, which is also the state capital. The map shows its 4 cities and towns and the 4 neighboring counties.
Suffolk County facts
- County seat
- Boston
- Population (2025 estimate)
- 791,891 −1.1% since 2020
- Land area
- 58 sq mi 13th largest of 14
- Water area
- 62 sq mi
- Population density
- 13,593 per sq mi
- Established
- 1643
- Named after
- Suffolk county of England
- Largest city
- Boston 672,973
- Median household income
- $95,631
- Cities and towns
- 4
- ZIP codes
- 39
- Time zone
- Eastern
- FIPS code
- 25025
Cities and towns in Suffolk County
Suffolk County has 4 incorporated cities, towns and villages. Populations count the people living inside Suffolk County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Boston (county seat) | City | 672,973 | |
| Revere | City | 60,141 | |
| Chelsea | City | 40,130 | |
| Winthrop Town | City | 18,647 |
ZIP codes in Suffolk County
39 ZIP codes reach into Suffolk County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 02108
- 02109
- 02110
- 02111
- 02113
- 02114
- 02115
- 02116
- 02118
- 02119
- 02120
- 02121
- 02122
- 02124
- 02125
- 02126
- 02127
- 02128
- 02129
- 02130
- 02131
- 02132
- 02133
- 02134
- 02135
- 02136
- 02149 also Middlesex County
- 02150
- 02151
- 02152
- 02163
- 02199
- 02203
- 02205
- 02210
- 02215 also Norfolk County
- 02445 also Norfolk County
- 02446 also Norfolk County
- 02467 also Norfolk and Middlesex counties
Population of Suffolk County, 2020–2025
Suffolk County shrank by 9,043 people (−1.1%) between April 2020 and July 2025: 16,779 more births than deaths and a net loss of 23,972 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 791,372 |
| 2021 | 777,600 |
| 2022 | 778,090 |
| 2023 | 784,637 |
| 2024 | 793,535 |
| 2025 | 791,891 |
Neighboring counties
- Norfolk County southwest · 739,749 people
- Essex County northeast · 826,653 people
- Middlesex County northwest · 1,669,979 people
- Plymouth County southeast · 546,829 people
Printable Suffolk 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) (76 KB)
- PNG (2400 px) (117 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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