| 1 | Mashantucket CDP (south) | 8,394 |
| 2 | South Windham CDP (south-southwest) | 7,137 |
| 3 | Gales Ferry CDP (northeast) | 7,000 |
| 4 | Colchester CDP (west-southwest) | 6,476 |
| 5 | Waterford CDP (west-northwest) | 6,345 |
| 6 | Willimantic CDP (west) | 6,227 |
| 7 | Jewett City borough (east-southeast) | 6,167 |
| 8 | Conning Towers-Nautilus Park CDP (northeast) | 6,002 |
| 9 | Norwich city (south) | 5,861 |
| 10 | Oxoboxo River CDP (west-southwest) | 5,648 |
| 11 | Norwich city (east-northeast) | 5,622 |
| 12 | Niantic CDP (north-northwest) | 5,506 |
| 13 | Niantic CDP (west-northwest) | 5,384 |
| 14 | New London city (east-southeast) | 5,382 |
| 15 | Waterford CDP (north) | 5,375 |
| 16 | Jewett City borough (west-northwest) | 5,317 |
| 17 | Niantic CDP (east-northeast) | 5,293 |
| 18 | Norwich city (north-northeast) | 5,215 |
| 19 | Oxoboxo River CDP (east-southeast) | 5,204 |
| 20 | Mashantucket CDP (east) | 5,154 |
| 21 | Long Hill CDP (east-southeast) | 5,026 |
| 22 | Colchester CDP (east) | 4,981 |
| 23 | Norwich city (west-northwest) | 4,958 |
| 24 | Mashantucket CDP (northwest) | 4,812 |
| 25 | Mashantucket CDP (west) | 4,723 |
| 26 | Waterford CDP (west-southwest) | 4,502 |
| 27 | Groton city (north-northwest) | 4,500 |
| 28 | Old Mystic CDP | 4,367 |
| 29 | Oxoboxo River CDP (west) | 4,247 |
| 30 | Pawcatuck CDP | 4,236 |
| 31 | Baltic CDP (east) | 4,213 |
| 32 | Oxoboxo River CDP (east-northeast) | 4,183 |
| 33 | Niantic CDP (south-southeast) | 4,154 |
| 34 | Norwich city (south-southwest) | 4,109 |
| 35 | Colchester CDP (north-northwest) | 4,048 |
| 36 | Willimantic CDP (east-southeast) | 4,028 |
| 37 | Stonington borough (east-southeast) | 3,979 |
| 38 | Poquonock Bridge CDP | 3,833 |
| 39 | South Windham CDP (northwest) | 3,794 |
| 40 | South Windham CDP (north) | 3,710 |
| 41 | Waterford CDP (south-southeast) | 3,687 |
| 42 | Stonington borough (south-southwest) | 3,661 |
| 43 | Mystic CDP (east-southeast) | 3,660 |
| 44 | Mystic CDP (west-northwest) | 3,650 |
| 45 | New London city (southwest) | 3,560 |
| 46 | Long Hill CDP (west-northwest) | 3,411 |
| 47 | Norwich city (south-southeast 2) | 3,402 |
| 48 | Willimantic CDP (northeast) | 3,347 |
| 49 | Gales Ferry CDP (south-southwest) | 3,144 |
| 50 | Norwich city (north-northwest) | 3,141 |
| 51 | Oxoboxo River CDP (south-southeast) | 3,130 |
| 52 | Gales Ferry CDP (north-northwest) | 2,971 |
| 53 | Norwich city (south-southeast 1) | 2,961 |
| 54 | Baltic CDP (north) | 2,945 |
| 55 | Waterford CDP (east-northeast) | 2,932 |
| 56 | Stonington borough (northwest) | 2,845 |
| 57 | South Windham CDP (northeast) | 2,799 |
| 58 | Conning Towers-Nautilus Park CDP (southwest) | 2,455 |
| 59 | Oxoboxo River CDP (north-northwest) | 2,373 |
| 60 | Groton Long Point borough | 2,314 |
| 61 | Waterford CDP (east) | 2,195 |
| 62 | Niantic CDP (north) | 2,071 |
| 63 | Baltic CDP (west-southwest) | 1,925 |
| 64 | Niantic CDP (south-southwest) | 1,523 |
| 65 | Gales Ferry CDP (south-southeast) | 1,304 |
| 66 | New London city (north) | 1,283 |
| 67 | Groton city (south-southeast) | 1,224 |