37 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Northampton township | 1 | 40,030 | 39,852 | 0.2% | 1,559 | 25.68 | Township |
| Easton | 2 | 30,507 | 28,084 | 1.62% | 7,156 | 4.26 | City |
| Palmer township | 3 | 22,304 | 22,290 | -0.19% | 2,174 | 10.26 | Township |
| Forks township | 4 | 16,742 | 16,126 | 0.86% | 1,385 | 12.09 | Township |
| Lower Saucon township | 5 | 11,010 | 11,080 | -0.05% | 454 | 24.27 | Township |
| Lehigh township | 6 | 10,761 | 10,763 | 0.1% | 367 | 29.34 | Township |
| Northampton | 7 | 10,424 | 10,373 | 0.1% | 4,219 | 2.47 | Borough |
| Moore township | 8 | 9,380 | 9,324 | 0.15% | 252 | 37.20 | Township |
| Upper Nazareth township | 9 | 8,586 | 8,146 | 1.05% | 1,174 | 7.31 | Township |
| Chestnut Hill | 10 | 8,116 | 6,135 | 7.14% | 2,677 | 3.03 | CDP |
| Lower Nazareth township | 11 | 7,092 | 6,930 | -0.28% | 527 | 13.47 | Township |
| Williams township | 12 | 6,665 | 6,569 | 0.62% | 367 | 18.16 | Township |
| Upper Mount Bethel township | 13 | 6,415 | 6,443 | 0.14% | 151 | 42.47 | Township |
| Hellertown | 14 | 6,113 | 6,122 | -0.03% | 4,659 | 1.31 | Borough |
| Nazareth | 15 | 6,074 | 6,041 | 0.12% | 3,832 | 1.58 | Borough |
| East Allen township | 16 | 5,475 | 5,014 | 1.54% | 376 | 14.55 | Township |
| Allen township | 17 | 5,451 | 5,468 | 0% | 503 | 10.85 | Township |
| Bangor | 18 | 5,089 | 5,186 | -0.37% | 3,411 | 1.49 | Borough |
| Wind Gap | 19 | 4,123 | 2,817 | 6.76% | 3,079 | 1.34 | Borough |
| Palmer Heights | 20 | 3,927 | 4,033 | 0.28% | 3,388 | 1.16 | CDP |
| Eastlawn Gardens | 21 | 3,593 | 3,338 | 0.53% | 2,069 | 1.74 | CDP |
| Pen Argyl | 22 | 3,430 | 3,509 | -0.46% | 2,556 | 1.34 | Borough |
| Bath | 23 | 2,913 | 2,828 | 0.59% | 3,226 | 0.90 | Borough |
| Lower Mount Bethel township | 24 | 2,897 | 2,913 | -0.03% | 122 | 23.76 | Township |
| Walnutport | 25 | 2,094 | 2,073 | 0.19% | 2,785 | 0.75 | Borough |
| Old Orchard | 26 | 1,674 | 1,807 | -2.96% | 2,293 | 0.73 | CDP |
| Roseto | 27 | 1,545 | 1,579 | -0.45% | 2,456 | 0.63 | Borough |
| Tatamy | 28 | 1,538 | 1,210 | 4.48% | 2,771 | 0.56 | Borough |
| Cherryville | 29 | 1,445 | 1,571 | -0.62% | 551 | 2.62 | CDP |
| Belfast | 30 | 1,232 | 1,305 | -0.16% | 1,002 | 1.23 | CDP |
| East Bangor | 31 | 1,098 | 1,120 | -0.36% | 1,321 | 0.83 | Borough |
| Stockertown | 32 | 910 | 917 | -0.11% | 938 | 0.97 | Borough |
| Portland | 33 | 477 | 486 | -0.42% | 988 | 0.48 | Borough |
| Martins Creek | 34 | 317 | 457 | -6.21% | 388 | 0.82 | CDP |
| Northampton township | 35 | 292 | 305 | -1.02% | 8 | 35.87 | Township |
| Chapman | 36 | 219 | 221 | 0% | 664 | 0.33 | Borough |
| Ackermanville | 37 | 198 | 398 | -12% | 145 | 1.37 | CDP |
Northampton township is the largest city in Northampton County, with a population of 40,030.
Ackermanville is the smallest city in Northampton County.
There are 37 cities in Northampton County, Pennsylvania.