30 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Malden | Middlesex County | 67,546 |
| Medford | Middlesex County | 60,401 |
| Marlborough | Middlesex County | 42,554 |
| Milford | Worcester County | 30,838 |
| Melrose | Middlesex County | 30,203 |
| Milton | Norfolk County | 29,057 |
| Marshfield | Plymouth County | 26,205 |
| Middleborough | Plymouth County | 25,099 |
| Mansfield | Bristol County | 24,185 |
| Marblehead | Essex County | 20,727 |
| Mashpee | Barnstable County | 15,479 |
| Millbury | Worcester County | 14,334 |
| Medway | Norfolk County | 14,006 |
| Medfield | Norfolk County | 13,483 |
| Maynard | Middlesex County | 10,918 |
| Middleton | Essex County | 10,021 |
| Millis | Norfolk County | 9,597 |
| Montague | Franklin County | 8,430 |
| Monson | Hampden County | 8,199 |
| Merrimac | Essex County | 6,863 |
| Mattapoisett | Plymouth County | 6,848 |
| Mendon | Worcester County | 6,515 |
| Manchester-by-the-Sea | Essex County | 5,506 |
| Marion | Plymouth County | 5,373 |
| Millville | Worcester County | 3,207 |
| Monterey | Berkshire County | 1,088 |
| Montgomery | Hampden County | 844 |
| Middlefield | Hampshire County | 400 |
| Mount Washington | Berkshire County | 157 |
| Monroe | Franklin County | 115 |