The largest county in Massachusetts
There are two right answers. By land area it is Worcester County; by population it is Middlesex County. Which one you want depends on what you meant by largest.
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025. Retrieved 30 August 2026.
By land area
| Rank | Name | Land area | Population |
|---|---|---|---|
| 1 | Worcester County | 1,511 sq mi | 888,502 |
| 2 | Berkshire County | 926.9 sq mi | 128,224 |
| 3 | Middlesex County | 817.9 sq mi | 1,669,979 |
| 4 | Franklin County | 699.2 sq mi | 70,698 |
| 5 | Plymouth County | 658.5 sq mi | 546,829 |
| 6 | Hampden County | 617 sq mi | 464,338 |
| 7 | Bristol County | 553.1 sq mi | 593,640 |
| 8 | Hampshire County | 527.2 sq mi | 164,065 |
| 9 | Essex County | 492.5 sq mi | 826,653 |
| 10 | Norfolk County | 396.1 sq mi | 739,749 |
By population
| Rank | Name | Population | Density |
|---|---|---|---|
| 1 | Middlesex County | 1,669,979 | 2,042 per sq mi |
| 2 | Worcester County | 888,502 | 588 per sq mi |
| 3 | Essex County | 826,653 | 1,678 per sq mi |
| 4 | Suffolk County | 791,891 | 13,593 per sq mi |
| 5 | Norfolk County | 739,749 | 1,868 per sq mi |
| 6 | Bristol County | 593,640 | 1,073 per sq mi |
| 7 | Plymouth County | 546,829 | 830 per sq mi |
| 8 | Hampden County | 464,338 | 753 per sq mi |
| 9 | Barnstable County | 233,539 | 592 per sq mi |
| 10 | Hampshire County | 164,065 | 311 per sq mi |
And the smallest
More on Massachusetts
Rebuilt from source data 30 August 2026. How these figures are produced.