29 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Boston | Suffolk County | 682,313 |
| Brockton | Plymouth County | 106,340 |
| Brookline | Norfolk County | 64,662 |
| Barnstable Town | Barnstable County | 49,704 |
| Billerica | Middlesex County | 43,965 |
| Beverly | Essex County | 43,703 |
| Braintree Town | Norfolk County | 39,497 |
| Bridgewater Town | Plymouth County | 29,383 |
| Belmont | Middlesex County | 27,701 |
| Burlington | Middlesex County | 27,301 |
| Bourne | Barnstable County | 20,544 |
| Bellingham | Norfolk County | 18,316 |
| Belchertown | Hampshire County | 15,337 |
| Bedford | Middlesex County | 15,112 |
| Brewster | Barnstable County | 10,466 |
| Blackstone | Worcester County | 9,478 |
| Boxford | Essex County | 8,465 |
| Berkley | Bristol County | 6,930 |
| Bolton | Worcester County | 5,845 |
| Barre | Worcester County | 5,689 |
| Boxborough | Middlesex County | 5,619 |
| Boylston | Worcester County | 5,123 |
| Brimfield | Hampden County | 3,757 |
| Brookfield | Worcester County | 3,528 |
| Berlin | Worcester County | 3,512 |
| Bernardston | Franklin County | 2,107 |
| Becket | Berkshire County | 1,921 |
| Buckland | Franklin County | 1,829 |
| Blandford | Hampden County | 1,212 |