| 1 | Durham CDP (south-southeast) | 7,182 |
| 2 | Portland CDP (southeast) | 6,432 |
| 3 | Chester Center CDP (southwest) | 6,219 |
| 4 | Lake Pocotopaug CDP | 6,017 |
| 5 | Portland CDP (east-northeast) | 5,895 |
| 6 | Portland CDP (north-northwest) | 5,753 |
| 7 | Middletown city (west) | 5,690 |
| 8 | Old Saybrook Center CDP (southwest) | 5,485 |
| 9 | Portland CDP (west-southwest) | 5,463 |
| 10 | Moodus CDP (west-northwest) | 5,462 |
| 11 | Portland CDP (west-northwest) | 5,178 |
| 12 | Saybrook Manor CDP | 5,030 |
| 13 | Middletown city (east-southeast 2) | 4,831 |
| 14 | Higganum CDP (west-southwest) | 4,737 |
| 15 | Deep River Center CDP (northwest) | 4,432 |
| 16 | Clinton CDP (north) | 4,250 |
| 17 | Durham CDP (south-southwest) | 4,236 |
| 18 | Deep River Center CDP (southeast) | 4,041 |
| 19 | Middletown city (south) | 4,025 |
| 20 | East Hampton CDP (northeast) | 3,997 |
| 21 | Westbrook Center CDP (west-southwest) | 3,910 |
| 22 | Higganum CDP (east-northeast) | 3,825 |
| 23 | Chester Center CDP (northeast) | 3,786 |
| 24 | Middletown city (northwest) | 3,773 |
| 25 | Middletown city (east) | 3,684 |
| 26 | Clinton CDP (southeast) | 3,656 |
| 27 | Portland CDP (east-southeast) | 3,526 |
| 28 | Moodus CDP (east-southeast) | 3,472 |
| 29 | Old Saybrook Center CDP (north-northwest) | 3,386 |
| 30 | Portland CDP (northwest) | 3,370 |
| 31 | Durham CDP (northwest) | 3,350 |
| 32 | Middletown city (east-southeast 1) | 3,330 |
| 33 | Clinton CDP (west-northwest) | 3,232 |
| 34 | Westbrook Center CDP (northwest) | 2,922 |
| 35 | East Hampton CDP (southwest) | 2,820 |
| 36 | Old Saybrook Center CDP (northeast) | 2,752 |
| 37 | Essex Village CDP (south-southwest) | 2,725 |
| 38 | Essex Village CDP (north-northeast) | 2,356 |
| 39 | Clinton CDP (south) | 2,179 |
| 40 | Portland CDP (south-southwest) | 2,144 |
| 41 | Durham CDP (north-northwest) | 1,864 |
| 42 | Durham CDP (east-southeast) | 1,692 |
| 43 | Old Saybrook Center CDP (east-southeast) | 1,506 |
| 44 | Middletown city (northeast) | 1,368 |