29 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Northampton | 1 | 40,404 | 39,852 | 0.36% | 1,573 | 26 | Township |
| Easton | 2 | 31,604 | 28,087 | 1.89% | 7,414 | 4 | City |
| Palmer | 3 | 22,940 | 22,287 | 0.73% | 2,236 | 10 | Township |
| Forks | 4 | 17,003 | 16,130 | 1.01% | 1,407 | 12 | Township |
| Lower Saucon | 5 | 11,167 | 11,085 | 0.35% | 460 | 24 | Township |
| Lehigh | 6 | 10,915 | 10,759 | 0.46% | 372 | 29 | Township |
| Northampton | 7 | 10,696 | 10,369 | 0.52% | 4,329 | 2 | Borough |
| Moore | 8 | 9,541 | 9,327 | 0.56% | 256 | 37 | Township |
| Upper Nazareth | 9 | 8,525 | 8,142 | 0.42% | 1,166 | 7 | Township |
| Lower Nazareth | 10 | 7,221 | 6,933 | 0.32% | 536 | 13 | Township |
| Williams | 11 | 6,798 | 6,570 | 0.95% | 374 | 18 | Township |
| Upper Mount Bethel | 12 | 6,480 | 6,442 | 0.36% | 153 | 42 | Township |
| Hellertown | 13 | 6,158 | 6,119 | 0.11% | 4,694 | 1 | Borough |
| Nazareth | 14 | 6,111 | 6,041 | 0.2% | 3,856 | 2 | Borough |
| Allen | 15 | 5,838 | 5,473 | 2.13% | 538 | 11 | Township |
| East Allen | 16 | 5,527 | 5,015 | 1.25% | 380 | 15 | Township |
| Bangor | 17 | 5,163 | 5,187 | -0.08% | 3,460 | 1 | Borough |
| Wind Gap | 18 | 4,028 | 2,819 | 5.28% | 3,008 | 1 | Borough |
| Pen Argyl | 19 | 3,468 | 3,516 | -0.23% | 2,584 | 1 | Borough |
| Bath | 20 | 2,936 | 2,842 | 0.55% | 3,251 | 1 | Borough |
| Lower Mount Bethel | 21 | 2,931 | 2,916 | 0.24% | 123 | 24 | Township |
| Walnutport | 22 | 2,111 | 2,077 | 0.29% | 2,807 | 1 | Borough |
| Roseto | 23 | 1,556 | 1,580 | -0.26% | 2,474 | 1 | Borough |
| Tatamy | 24 | 1,493 | 1,184 | 3.61% | 2,690 | 1 | Borough |
| East Bangor | 25 | 1,106 | 1,121 | -0.18% | 1,331 | 1 | Borough |
| Stockertown | 26 | 912 | 915 | 0% | 940 | 1 | Borough |
| Portland | 27 | 484 | 486 | 0% | 1,002 | 0 | Borough |
| Northampton | 28 | 289 | 305 | -1.03% | 8 | 36 | Township |
| Chapman | 29 | 220 | 220 | 0% | 667 | 0 | Borough |
Northampton is the largest city in Northampton County, with a population of 40,404.
Chapman is the smallest city in Northampton County, with a population of 220.
There are 29 cities in Northampton County, Pennsylvania.