| 1 | Unincorporated (west 1) | 10,015 |
| 2 | Breinigsville CDP (east-southeast) | 8,654 |
| 3 | Allentown city (south-southeast 3) | 7,419 |
| 4 | DeSales University CDP | 7,072 |
| 5 | Allentown city (southwest 1) | 7,040 |
| 6 | Allentown city (south-southeast 2) | 7,020 |
| 7 | Allentown city (south-southeast 1) | 6,899 |
| 8 | Wescosville CDP (west) | 6,805 |
| 9 | Alburtis borough | 6,800 |
| 10 | Slatedale CDP | 6,559 |
| 11 | Catasauqua borough | 6,491 |
| 12 | Dorneyville CDP (east-southeast) | 6,196 |
| 13 | Allentown city (east-southeast) | 6,124 |
| 14 | Emmaus borough (north-northwest) | 6,104 |
| 15 | Cetronia CDP | 6,008 |
| 16 | Fullerton CDP (west-northwest) | 5,968 |
| 17 | Allentown city (west-southwest 3) | 5,896 |
| 18 | Unincorporated (northwest 2) | 5,876 |
| 19 | Unincorporated (east-southeast 2) | 5,657 |
| 20 | Emmaus borough (south-southeast) | 5,623 |
| 21 | Hokendauqua CDP | 5,317 |
| 22 | Egypt CDP | 5,313 |
| 23 | Unincorporated (north) | 5,176 |
| 24 | Allentown city (west-southwest 4) | 5,063 |
| 25 | Unincorporated (south) | 4,984 |
| 26 | Unincorporated (west 2) | 4,980 |
| 27 | Fountain Hill borough | 4,811 |
| 28 | Unincorporated (east-northeast) | 4,721 |
| 29 | Allentown city (northwest) | 4,702 |
| 30 | Allentown city (north-northeast 3) | 4,658 |
| 31 | Allentown city (west-southwest 2) | 4,655 |
| 32 | Unincorporated (south-southeast 2) | 4,626 |
| 33 | Allentown city (east-northeast 2) | 4,623 |
| 34 | Allentown city (northeast 2) | 4,578 |
| 35 | Fullerton CDP (east-southeast) | 4,536 |
| 36 | Allentown city (west) | 4,519 |
| 37 | Bethlehem city (east-southeast) | 4,497 |
| 38 | Schnecksville CDP (north-northwest) | 4,473 |
| 39 | Ancient Oaks CDP (south-southeast) | 4,459 |
| 40 | Unincorporated (east-southeast 1) | 4,429 |
| 41 | Allentown city (northeast 1) | 4,413 |
| 42 | Breinigsville CDP (west-northwest) | 4,361 |
| 43 | Allentown city (north 2) | 4,336 |
| 44 | Allentown city (west-northwest 2) | 4,316 |
| 45 | Fullerton CDP (north-northeast) | 4,289 |
| 46 | Slatington borough | 4,277 |
| 47 | New Tripoli CDP | 4,248 |
| 48 | Allentown city (north-northeast 1) | 4,214 |
| 49 | Wescosville CDP (east) | 4,184 |
| 50 | Ancient Oaks CDP (north-northwest) | 4,180 |
| 51 | Allentown city (west-northwest 1) | 4,158 |
| 52 | Dorneyville CDP (west-northwest) | 4,113 |
| 53 | Bethlehem city (north-northwest) | 4,084 |
| 54 | Allentown city (north 1) | 4,080 |
| 55 | Trexlertown CDP | 4,070 |
| 56 | Allentown city (southeast) | 4,048 |
| 57 | Laurys Station CDP (northeast) | 4,036 |
| 58 | Bethlehem city (south-southeast) | 3,967 |
| 59 | Unincorporated (southeast) | 3,848 |
| 60 | Allentown city (north-northwest) | 3,788 |
| 61 | Bethlehem city (northwest) | 3,783 |
| 62 | Fullerton CDP (south) | 3,705 |
| 63 | Laurys Station CDP (southwest) | 3,690 |
| 64 | Unincorporated (south-southwest) | 3,636 |
| 65 | Bethlehem city (southwest) | 3,509 |
| 66 | Schnecksville CDP (south-southeast) | 3,503 |
| 67 | Allentown city (west-southwest 1) | 3,437 |
| 68 | Coplay borough | 3,423 |
| 69 | Unincorporated (northwest 1) | 3,333 |
| 70 | Unincorporated (south-southeast 1) | 3,313 |
| 71 | Macungie borough | 3,247 |
| 72 | Allentown city (southwest 2) | 2,829 |
| 73 | Allentown city (south) | 2,711 |
| 74 | Unincorporated (east) | 2,688 |
| 75 | Allentown city (east) | 2,687 |
| 76 | Allentown city (east-northeast 1) | 2,580 |
| 77 | Allentown city (east-northeast 3) | 2,474 |
| 78 | Coopersburg borough | 2,384 |
| 79 | Unincorporated (west-northwest) | 2,187 |
| 80 | Allentown city (north-northeast 2) | 2,053 |
| 81 | Unincorporated (north-northeast) | 1,880 |