30 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Malden | Middlesex County | 68,399 |
| Medford | Middlesex County | 60,904 |
| Marlborough | Middlesex County | 42,939 |
| Milford | Worcester County | 31,036 |
| Melrose | Middlesex County | 30,468 |
| Milton | Norfolk County | 29,303 |
| Marshfield | Plymouth County | 26,367 |
| Middleborough | Plymouth County | 25,351 |
| Mansfield | Bristol County | 24,293 |
| Marblehead | Essex County | 20,878 |
| Mashpee | Barnstable County | 15,476 |
| Millbury | Worcester County | 14,495 |
| Medway | Norfolk County | 14,176 |
| Medfield | Norfolk County | 13,632 |
| Maynard | Middlesex County | 11,016 |
| Middleton | Essex County | 10,083 |
| Millis | Norfolk County | 9,856 |
| Montague | Franklin County | 8,423 |
| Monson | Hampden County | 8,234 |
| Mattapoisett | Plymouth County | 6,933 |
| Merrimac | Essex County | 6,916 |
| Mendon | Worcester County | 6,589 |
| Manchester-by-the-Sea | Essex County | 5,545 |
| Marion | Plymouth County | 5,405 |
| Millville | Worcester County | 3,227 |
| Monterey | Berkshire County | 1,091 |
| Montgomery | Hampden County | 851 |
| Middlefield | Hampshire County | 403 |
| Mount Washington | Berkshire County | 157 |
| Monroe | Franklin County | 115 |