| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Allentown | 1 | 126,067 | 125,714 | 0.02% | 7,178 | 18 | City |
| Bethlehem | 2 | 80,563 | 75,698 | 1.15% | 4,215 | 19 | City |
| Lower Macungie | 3 | 33,909 | 32,437 | 1.2% | 1,515 | 22 | Township |
| Upper Macungie | 4 | 30,032 | 26,473 | 1.46% | 1,151 | 26 | Township |
| Whitehall | 5 | 29,326 | 29,154 | -0.27% | 2,333 | 13 | Township |
| Bethlehem | 6 | 26,810 | 25,886 | 0.15% | 1,859 | 14 | Township |
| South Whitehall | 7 | 21,617 | 21,064 | -0.18% | 1,266 | 17 | Township |
| Upper Saucon | 8 | 18,303 | 16,983 | 0.47% | 748 | 24 | Township |
| North Whitehall | 9 | 16,057 | 15,649 | 0.15% | 571 | 28 | Township |
| Whitehall | 10 | 14,416 | 15,034 | -0.72% | 4,336 | 3 | Borough |
| Emmaus | 11 | 12,662 | 11,634 | 1.18% | 4,374 | 3 | Borough |
| Upper Milford | 12 | 8,252 | 7,825 | -0.02% | 459 | 18 | Township |
| Catasauqua | 13 | 6,607 | 6,515 | 0.26% | 5,114 | 1 | Borough |
| Weisenberg | 14 | 5,119 | 4,975 | 0.33% | 191 | 27 | Township |
| Fountain Hill | 15 | 4,841 | 4,828 | 0.12% | 6,586 | 1 | Borough |
| Slatington | 16 | 4,301 | 4,281 | 0.12% | 3,256 | 1 | Borough |
| Lynn | 17 | 4,291 | 4,219 | -0.12% | 104 | 41 | Township |
| Lower Milford | 18 | 3,905 | 3,859 | 0.18% | 198 | 20 | Township |
| Coplay | 19 | 3,579 | 3,342 | 1.33% | 5,867 | 1 | Borough |
| Heidelberg | 20 | 3,416 | 3,345 | 0.15% | 139 | 25 | Township |
| Macungie | 21 | 3,410 | 3,253 | 0.44% | 3,448 | 1 | Borough |
| North Catasauqua | 22 | 3,266 | 2,972 | 1.15% | 4,549 | 1 | Borough |
| Freemansburg | 23 | 3,028 | 2,870 | 0.83% | 4,344 | 1 | Borough |
| Alburtis | 24 | 2,613 | 2,586 | 0.15% | 3,696 | 1 | Borough |
| Coopersburg | 25 | 2,549 | 2,449 | 0.55% | 2,732 | 1 | Borough |
| Lowhill | 26 | 2,329 | 2,273 | -0.09% | 166 | 14 | Township |
Allentown is the largest city in Lehigh County, with a population of 126,067.
Lowhill is the smallest city in Lehigh County, with a population of 2,329.
There are 26 cities in Lehigh County, Pennsylvania.