40 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Allentown | 1 | 124,315 | 125,727 | -0.23% | 7,078 | 17.56 | City |
| Bethlehem | 2 | 80,034 | 75,699 | 1.1% | 4,187 | 19.11 | City |
| Lower Macungie township | 3 | 32,510 | 32,413 | -0.02% | 1,453 | 22.38 | Township |
| Upper Macungie township | 4 | 29,748 | 26,485 | 2.16% | 1,140 | 26.09 | Township |
| Whitehall township | 5 | 29,087 | 29,167 | -0.04% | 2,314 | 12.57 | Township |
| Bethlehem township | 6 | 26,638 | 25,882 | 0.57% | 1,847 | 14.42 | Township |
| South Whitehall township | 7 | 21,653 | 21,067 | 0.58% | 1,268 | 17.08 | Township |
| Upper Saucon township | 8 | 18,337 | 16,981 | 1.94% | 749 | 24.47 | Township |
| Fullerton | 9 | 16,716 | 15,415 | 0.72% | 4,556 | 3.67 | CDP |
| North Whitehall township | 10 | 15,756 | 15,637 | 0.01% | 561 | 28.10 | Township |
| Whitehall | 11 | 14,329 | 15,044 | -0.99% | 4,309 | 3.33 | Borough |
| Emmaus | 12 | 12,267 | 11,641 | 1.03% | 4,237 | 2.90 | Borough |
| Breinigsville | 13 | 10,259 | 7,574 | 4.14% | 3,042 | 3.37 | CDP |
| Upper Milford township | 14 | 8,288 | 7,816 | 1.1% | 461 | 17.96 | Township |
| Catasauqua | 15 | 6,440 | 6,512 | -0.22% | 4,985 | 1.29 | Borough |
| Dorneyville | 16 | 5,265 | 4,707 | 1.09% | 2,430 | 2.17 | CDP |
| Weisenberg township | 17 | 5,056 | 4,974 | 0.5% | 189 | 26.77 | Township |
| Fountain Hill | 18 | 4,780 | 4,824 | -0.19% | 6,503 | 0.73 | Borough |
| Lynn township | 19 | 4,253 | 4,236 | 0.09% | 103 | 41.25 | Township |
| Slatington | 20 | 4,230 | 4,279 | -0.24% | 3,202 | 1.32 | Borough |
| Schnecksville | 21 | 4,132 | 4,022 | 1.95% | 1,475 | 2.80 | CDP |
| Lower Milford township | 22 | 3,831 | 3,858 | -0.13% | 195 | 19.70 | Township |
| Coplay | 23 | 3,595 | 3,342 | 1.44% | 5,893 | 0.61 | Borough |
| Heidelberg township | 24 | 3,337 | 3,326 | 0.03% | 135 | 24.65 | Township |
| Macungie | 25 | 3,268 | 3,255 | 0.09% | 3,304 | 0.99 | Borough |
| Egypt | 26 | 3,150 | 2,392 | 1.65% | 2,141 | 1.47 | CDP |
| North Catasauqua | 27 | 3,045 | 2,970 | 0.5% | 4,241 | 0.72 | Borough |
| Cetronia | 28 | 2,971 | 2,844 | 7.14% | 3,663 | 0.81 | CDP |
| Freemansburg | 29 | 2,910 | 2,869 | 0.28% | 4,175 | 0.70 | Borough |
| Hokendauqua | 30 | 2,855 | 2,736 | -1.21% | 2,591 | 1.10 | CDP |
| Alburtis | 31 | 2,567 | 2,591 | -0.19% | 3,631 | 0.71 | Borough |
| Coopersburg | 32 | 2,504 | 2,458 | 0.36% | 2,684 | 0.93 | Borough |
| Lowhill township | 33 | 2,340 | 2,288 | 0.6% | 167 | 14.01 | Township |
| Trexlertown | 34 | 1,859 | 2,120 | -0.48% | 895 | 2.08 | CDP |
| Cementon | 35 | 1,322 | 1,563 | -1.05% | 2,031 | 0.65 | CDP |
| Stiles | 36 | 1,093 | 1,195 | -0.09% | 5,084 | 0.21 | CDP |
| DeSales University | 37 | 939 | 929 | -0.11% | 1,570 | 0.60 | CDP |
| New Tripoli | 38 | 627 | 840 | -2.79% | 684 | 0.92 | CDP |
| Laurys Station | 39 | 599 | 925 | -6.7% | 366 | 1.64 | CDP |
| Slatedale | 40 | 574 | 493 | 1.41% | 1,926 | 0.30 | CDP |
Allentown is the largest city in Lehigh County, with a population of 124,315.
Slatedale is the smallest city in Lehigh County.
There are 40 cities in Lehigh County, Pennsylvania.