| Lake | County | Latitude | Longitude |
| Manet Lake | Norfolk | 42.267499 | -70.958591 |
| Mare Meadow Reservoi | Worcester | 42.501058 | -71.931327 |
| Marys Lake | Dukes | 41.506124 | -70.713565 |
| Mascopic Lake | Middlesex | 42.678114 | -71.388649 |
| Massapoag Lake | Norfolk | 42.101893 | -71.177983 |
| Massapoug | Worcester | 42.555440 | -71.718415 |
| McClean Reservoir | Hampden | 42.179442 | -72.670185 |
| Meadow Brook | Plymouth | 42.086650 | -70.960388 |
| Meadow Lake | Berkshire | 42.257453 | -73.101824 |
| Metacomet Lake | Hampshire | 42.305643 | -72.431313 |
| Middle Cove | Dukes | 41.356747 | -70.639006 |
| Middle Reservoir | Middlesex | 42.454145 | -71.114347 |
| Mill Brook | Norfolk | 42.205417 | -71.256758 |
| Mill Brook Reservoir | Berkshire | 42.396485 | -73.212300 |
| Millham Reservoir | Middlesex | 42.342829 | -71.608319 |
| Millvale Reservoir | Essex | 42.792390 | -71.029800 |
| Mine Brook | Norfolk | 42.089346 | -71.424839 |
| Miscoe Lake | Norfolk | 42.019034 | -71.420752 |
| Mishawum Lake | Middlesex | 42.508094 | -71.137548 |
| Mohawk Lake | Berkshire | 42.295568 | -73.356813 |
| Mona Lake | Hampden | 42.142793 | -72.521031 |
| Moores Brook | Essex | 42.465896 | -70.985594 |
| Morewood Lake | Berkshire | 42.426084 | -73.251149 |
| Morey Hole | Plymouth | 41.868294 | -70.557907 |
| Morse Reservoir | Worcester | 42.516540 | -71.789066 |
| Mount Williams Reser | Berkshire | 42.684997 | -73.152985 |
| Mountain Lake | Hampden | 42.193192 | -72.580583 |
| Mountain Park Reserv | Hampden | 42.252590 | -72.636584 |
| Mountain Street Rese | Franklin | 42.405706 | -72.670098 |
| Muddy Brook | Worcester | 42.126080 | -71.562444 |
| Muddy Cove | Dukes | 41.373141 | -70.664033 |