29 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Boston | Suffolk County | 691,168 |
| Brockton | Plymouth County | 106,892 |
| Brookline | Norfolk County | 65,399 |
| Barnstable Town | Barnstable County | 49,577 |
| Billerica | Middlesex County | 44,952 |
| Beverly | Essex County | 44,183 |
| Braintree Town | Norfolk County | 39,860 |
| Bridgewater Town | Plymouth County | 29,599 |
| Belmont | Middlesex County | 27,960 |
| Burlington | Middlesex County | 27,625 |
| Bourne | Barnstable County | 20,580 |
| Bellingham | Norfolk County | 18,634 |
| Belchertown | Hampshire County | 15,302 |
| Bedford | Middlesex County | 15,269 |
| Brewster | Barnstable County | 10,485 |
| Blackstone | Worcester County | 9,582 |
| Boxford | Essex County | 8,596 |
| Berkley | Bristol County | 6,968 |
| Bolton | Worcester County | 5,881 |
| Barre | Worcester County | 5,747 |
| Boxborough | Middlesex County | 5,673 |
| Boylston | Worcester County | 5,182 |
| Brimfield | Hampden County | 3,781 |
| Brookfield | Worcester County | 3,556 |
| Berlin | Worcester County | 3,545 |
| Bernardston | Franklin County | 2,105 |
| Becket | Berkshire County | 1,920 |
| Buckland | Franklin County | 1,840 |
| Blandford | Hampden County | 1,215 |