26 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Allentown | 1 | 127,841 | 125,731 | 0.28% | 7,279 | 18 | City |
| Bethlehem | 2 | 81,326 | 75,706 | 1.17% | 4,255 | 19 | City |
| Lower Macungie | 3 | 34,124 | 32,422 | 1.3% | 1,525 | 22 | Township |
| Upper Macungie | 4 | 30,450 | 26,473 | 1.95% | 1,167 | 26 | Township |
| Whitehall | 5 | 30,278 | 29,160 | 1.04% | 2,408 | 13 | Township |
| Bethlehem | 6 | 27,381 | 25,879 | 1.22% | 1,898 | 14 | Township |
| South Whitehall | 7 | 22,298 | 21,068 | 1.09% | 1,306 | 17 | Township |
| Upper Saucon | 8 | 19,139 | 16,981 | 2.42% | 782 | 24 | Township |
| North Whitehall | 9 | 16,423 | 15,633 | 1.13% | 585 | 28 | Township |
| Whitehall | 10 | 14,499 | 15,035 | -0.61% | 4,361 | 3 | Borough |
| Emmaus | 11 | 12,651 | 11,640 | 1.35% | 4,370 | 3 | Borough |
| Upper Milford | 12 | 8,542 | 7,824 | 1.41% | 476 | 18 | Township |
| Catasauqua | 13 | 6,681 | 6,512 | 0.42% | 5,171 | 1 | Borough |
| Weisenberg | 14 | 5,240 | 4,974 | 1.22% | 196 | 27 | Township |
| Fountain Hill | 15 | 4,908 | 4,824 | 0.29% | 6,678 | 1 | Borough |
| Lynn | 16 | 4,440 | 4,234 | 1.19% | 108 | 41 | Township |
| Slatington | 17 | 4,356 | 4,281 | 0.3% | 3,298 | 1 | Borough |
| Lower Milford | 18 | 3,991 | 3,858 | 0.99% | 203 | 20 | Township |
| Coplay | 19 | 3,662 | 3,341 | 1.5% | 6,003 | 1 | Borough |
| Heidelberg | 20 | 3,484 | 3,326 | 1.19% | 141 | 25 | Township |
| Macungie | 21 | 3,375 | 3,254 | 0.6% | 3,413 | 1 | Borough |
| North Catasauqua | 22 | 3,204 | 2,969 | 1.23% | 4,462 | 1 | Borough |
| Freemansburg | 23 | 3,025 | 2,869 | 0.87% | 4,340 | 1 | Borough |
| Alburtis | 24 | 2,642 | 2,591 | 0.34% | 3,737 | 1 | Borough |
| Coopersburg | 25 | 2,571 | 2,460 | 0.74% | 2,756 | 1 | Borough |
| Lowhill | 26 | 2,416 | 2,288 | 1.17% | 172 | 14 | Township |
Allentown is the largest city in Lehigh County, with a population of 127,841.
Lowhill is the smallest city in Lehigh County, with a population of 2,416.
There are 26 cities in Lehigh County, Pennsylvania.