| City | County | 2026 Pop. ↓ |
|---|---|---|
| Cambridge | Middlesex County | 123,339 |
| Chicopee | Hampden County | 55,329 |
| Chelsea | Suffolk County | 40,086 |
| Chelmsford | Middlesex County | 39,269 |
| Canton | Norfolk County | 25,342 |
| Concord | Middlesex County | 18,184 |
| Clinton | Worcester County | 15,691 |
| Charlton | Worcester County | 13,737 |
| Carver | Plymouth County | 12,046 |
| Cohasset | Norfolk County | 8,454 |
| Chatham | Barnstable County | 6,755 |
| Carlisle | Middlesex County | 5,290 |
| Cheshire | Berkshire County | 3,157 |
| Conway | Franklin County | 1,744 |
| Colrain | Franklin County | 1,668 |
| Clarksburg | Berkshire County | 1,619 |
| Chilmark | Dukes County | 1,244 |
| Chester | Hampden County | 1,225 |
| Charlemont | Franklin County | 1,159 |
| Chesterfield | Hampshire County | 1,146 |
| Cummington | Hampshire County | 798 |