26 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Allentown | 1 | 127,489 | 125,731 | 0.28% | 7,259 | 18 | City |
| Bethlehem | 2 | 80,389 | 75,706 | 1.18% | 4,206 | 19 | City |
| Lower Macungie | 3 | 33,685 | 32,422 | 1.32% | 1,505 | 22 | Township |
| Whitehall | 4 | 29,967 | 29,160 | 1.05% | 2,384 | 13 | Township |
| Upper Macungie | 5 | 29,867 | 26,473 | 1.99% | 1,145 | 26 | Township |
| Bethlehem | 6 | 27,052 | 25,879 | 1.23% | 1,875 | 14 | Township |
| South Whitehall | 7 | 22,058 | 21,068 | 1.1% | 1,292 | 17 | Township |
| Upper Saucon | 8 | 18,686 | 16,981 | 2.48% | 764 | 24 | Township |
| North Whitehall | 9 | 16,240 | 15,633 | 1.14% | 578 | 28 | Township |
| Whitehall | 10 | 14,588 | 15,035 | -0.61% | 4,387 | 3 | Borough |
| Emmaus | 11 | 12,482 | 11,640 | 1.36% | 4,312 | 3 | Borough |
| Upper Milford | 12 | 8,423 | 7,824 | 1.43% | 469 | 18 | Township |
| Catasauqua | 13 | 6,653 | 6,512 | 0.42% | 5,149 | 1 | Borough |
| Weisenberg | 14 | 5,177 | 4,974 | 1.23% | 193 | 27 | Township |
| Fountain Hill | 15 | 4,894 | 4,824 | 0.29% | 6,659 | 1 | Borough |
| Lynn | 16 | 4,388 | 4,234 | 1.2% | 106 | 41 | Township |
| Slatington | 17 | 4,343 | 4,281 | 0.28% | 3,288 | 1 | Borough |
| Lower Milford | 18 | 3,952 | 3,858 | 1% | 201 | 20 | Township |
| Coplay | 19 | 3,608 | 3,341 | 1.49% | 5,915 | 1 | Borough |
| Heidelberg | 20 | 3,443 | 3,326 | 1.21% | 140 | 25 | Township |
| Macungie | 21 | 3,355 | 3,254 | 0.6% | 3,392 | 1 | Borough |
| North Catasauqua | 22 | 3,165 | 2,969 | 1.25% | 4,408 | 1 | Borough |
| Freemansburg | 23 | 2,999 | 2,869 | 0.87% | 4,303 | 1 | Borough |
| Alburtis | 24 | 2,633 | 2,591 | 0.3% | 3,724 | 1 | Borough |
| Coopersburg | 25 | 2,552 | 2,460 | 0.71% | 2,735 | 1 | Borough |
| Lowhill | 26 | 2,388 | 2,288 | 1.19% | 170 | 14 | Township |
Allentown is the largest city in Lehigh County, with a population of 127,489.
Lowhill is the smallest city in Lehigh County, with a population of 2,388.
There are 26 cities in Lehigh County, Pennsylvania.