| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Macedonia | city | Connecticut | United States | 41.74 | -73.50 | 830 | |
| Madison | city | Connecticut | United States | 41.28 | -72.60 | 68 | |
| Manchester | city | Connecticut | United States | 41.78 | -72.52 | 226 | |
| Manchester Green | city | Connecticut | United States | 41.79 | -72.50 | 403 | |
| Manitock Spring | city | Connecticut | United States | 41.35 | -72.16 | 98 | |
| Mansfield Center | city | Connecticut | United States | 41.77 | -72.20 | 291 | |
| Mansfield City | city | Connecticut | United States | 41.77 | -72.23 | 830 | |
| Mansfield Depot | city | Connecticut | United States | 41.80 | -72.31 | 298 | |
| Mansfield Four Corners | city | Connecticut | United States | 41.83 | -72.27 | 830 | |
| Mansfield Hollow | city | Connecticut | United States | 41.76 | -72.19 | 259 | |
| Marble Dale | city | Connecticut | United States | 41.66 | -73.37 | 830 | |
| Margerie Manor | city | Connecticut | United States | 41.45 | -73.47 | 830 | |
| Marion | city | Connecticut | United States | 41.56 | -72.93 | 187 | |
| Marlborough | city | Connecticut | United States | 41.63 | -72.46 | 413 | |
| Maromas | city | Connecticut | United States | 41.54 | -72.56 | 78 | |
| Mashapaug | city | Connecticut | United States | 42.03 | -72.14 | 830 | |
| Massapeag | city | Connecticut | United States | 41.46 | -72.08 | 19 | |
| Massomuck (historical) | city | Connecticut | United States | 41.90 | -71.96 | 830 | |
| Maushantuxet (historical) | city | Connecticut | United States | 41.44 | -72.02 | 298 | |
| Mayberry Village | city | Connecticut | United States | 41.78 | -72.59 | 98 | |
| McClaveville | city | Connecticut | United States | 42.04 | -73.10 | 1669 | |
| Meadowbrook | city | Connecticut | United States | 41.49 | -72.88 | 298 | |
| Meadowgate | city | Connecticut | United States | 41.95 | -72.79 | 200 | |
| Mechanicsville | city | Connecticut | United States | 41.94 | -71.89 | 377 | |
| Mechanicsville | city | Connecticut | United States | 41.97 | -72.79 | 196 | |
| Melrose | city | Connecticut | United States | 41.94 | -72.52 | 144 | |
| Melville Village | city | Connecticut | United States | 41.19 | -73.23 | 114 | |
| Meriden | city | Connecticut | United States | 41.54 | -72.81 | 196 | |
| Merrow | city | Connecticut | United States | 41.82 | -72.31 | 830 | |
| Merwinsville | city | Connecticut | United States | 41.65 | -73.48 | 275 | |
| Miami Shores | city | Connecticut | United States | 41.28 | -72.28 | 0 | |
| Mianus | city | Connecticut | United States | 41.04 | -73.59 | 22 | |
| Middle Beach | city | Connecticut | United States | 41.27 | -72.59 | 0 | |
| Middle Haddam | city | Connecticut | United States | 41.55 | -72.55 | 137 | |
| Middlebury | city | Connecticut | United States | 41.53 | -73.13 | 830 | |
| Middlefield | city | Connecticut | United States | 41.52 | -72.71 | 196 | |
| Middletown | city | Connecticut | United States | 41.56 | -72.65 | 13 | |
| Midway | city | Connecticut | United States | 41.34 | -72.03 | 72 | |
| Milestone Corner | city | Connecticut | United States | 41.52 | -72.27 | 830 | |
| Milford | city | Connecticut | United States | 41.22 | -73.06 | 9 | |
| Milford Lawns | city | Connecticut | United States | 41.22 | -73.01 | 49 | |
| Milfordas | city | Connecticut | United States | 41.22 | -73.06 | 9 | |
| Mill Brook | city | Connecticut | United States | 41.96 | -73.12 | 1200 | |
| Mill Hill | city | Connecticut | United States | 41.18 | -73.16 | 19 | |
| Mill Plain | city | Connecticut | United States | 41.40 | -73.52 | 830 | |
| Mill Plain | city | Connecticut | United States | 41.15 | -73.27 | 55 | |
| Mill Plain | city | Connecticut | United States | 41.56 | -73.01 | 830 | |
| Mill Pond Village | city | Connecticut | United States | 41.92 | -72.54 | 160 | |
| Millbrook | city | Connecticut | United States | 41.38 | -72.89 | 141 | |
| Milldale | city | Connecticut | United States | 41.57 | -72.89 | 131 | |
| Miller Memorial Community | city | Connecticut | United States | 41.53 | -72.80 | 298 | |
| Millington | city | Connecticut | United States | 41.49 | -72.36 | 830 | |
| Millstone | city | Connecticut | United States | 41.31 | -72.17 | 0 | |
| Millville | city | Connecticut | United States | 41.49 | -73.07 | 265 | |
| Millville (historical) | city | Connecticut | United States | 41.12 | -73.50 | 196 | |
| Milton | city | Connecticut | United States | 41.77 | -73.27 | 1010 | |
| Minortown | city | Connecticut | United States | 41.58 | -73.17 | 830 | |
| Miramichi | city | Connecticut | United States | 41.55 | -72.70 | 298 | |
| Miry Brook | city | Connecticut | United States | 41.37 | -73.48 | 830 | |
| Mitcheltown | city | Connecticut | United States | 41.86 | -73.46 | 898 | |
| Mixville | city | Connecticut | United States | 41.52 | -72.94 | 200 | |
| Mohegaanit | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Mohegan | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Mohegan (historical) | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Mohegan people | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Moheganen | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Mohegani | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Moheganoj | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Moheganowie | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Mohegans | city | Connecticut | United States | 41.48 | -72.10 | 308 | |
| Momauguin | city | Connecticut | United States | 41.25 | -72.88 | 6 | |
| Monroe | city | Connecticut | United States | 41.33 | -73.21 | 830 | |
| Montowese | city | Connecticut | United States | 41.35 | -72.86 | 88 | |
| Montville Center | city | Connecticut | United States | 41.48 | -72.15 | 311 | |
| Moodus | city | Connecticut | United States | 41.50 | -72.45 | 236 | |
| Mooreville | city | Connecticut | United States | 41.91 | -73.06 | 1000 | |
| Moosup | city | Connecticut | United States | 41.71 | -71.88 | 265 | |
| Morgan Fair Corners | city | Connecticut | United States | 41.41 | -73.31 | 830 | |
| Morningside | city | Connecticut | United States | 41.21 | -73.01 | 0 | |
| Morningside Park | city | Connecticut | United States | 41.35 | -72.13 | 88 | |
| Morningside Park | city | Connecticut | United States | 41.34 | -72.14 | 62 | |
| Morris | city | Connecticut | United States | 41.68 | -73.20 | 1099 | |
| Morris Cove | city | Connecticut | United States | 41.26 | -72.89 | 26 | |
| Mount Carmel | city | Connecticut | United States | 41.42 | -72.91 | 124 | |
| Mount Carmel Center | city | Connecticut | United States | 41.44 | -72.91 | 118 | |
| Mount Hope | city | Connecticut | United States | 41.82 | -72.17 | 334 | |
| Mount Parnassus | city | Connecticut | United States | 41.47 | -72.41 | 830 | |
| Mount Pleasant Housing | city | Connecticut | United States | 41.67 | -72.80 | 272 | |
| Mountaincrest | city | Connecticut | United States | 41.47 | -72.94 | 387 | |
| Mudgetown | city | Connecticut | United States | 41.90 | -73.48 | 830 | |
| Murray | city | Connecticut | United States | 41.19 | -73.29 | 288 | |
| Myrtle Beach | city | Connecticut | United States | 41.20 | -73.08 | 0 | |
| Mystic | city | Connecticut | United States | 41.35 | -71.97 | 3 | |
| Mystic Seaport | city | Connecticut | United States | 41.36 | -71.97 | 3 |