Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Northampton township | 1 | 39,951 | 39,852 | 0.2% | 1,556 | 25.7 | Township |
| Easton | 2 | 30,022 | 28,084 | 1.64% | 7,042 | 4.3 | City |
| Palmer township | 3 | 22,347 | 22,290 | -0.19% | 2,178 | 10.3 | Township |
| Forks township | 4 | 16,599 | 16,126 | 0.87% | 1,374 | 12.1 | Township |
| Lower Saucon township | 5 | 11,016 | 11,080 | -0.05% | 454 | 24.3 | Township |
| Lehigh township | 6 | 10,750 | 10,763 | 0.1% | 366 | 29.3 | Township |
| Northampton | 7 | 10,414 | 10,373 | 0.1% | 4,214 | 2.5 | Borough |
| Moore township | 8 | 9,366 | 9,324 | 0.15% | 252 | 37.2 | Township |
| Upper Nazareth township | 9 | 8,497 | 8,146 | 1.06% | 1,162 | 7.3 | Township |
| Lower Nazareth township | 10 | 7,112 | 6,930 | -0.28% | 528 | 13.5 | Township |
| Williams township | 11 | 6,624 | 6,569 | 0.62% | 365 | 18.2 | Township |
| Upper Mount Bethel township | 12 | 6,406 | 6,443 | 0.14% | 151 | 42.5 | Township |
| Hellertown | 13 | 6,115 | 6,122 | -0.03% | 4,661 | 1.3 | Borough |
| Nazareth | 14 | 6,067 | 6,041 | 0.1% | 3,828 | 1.6 | Borough |
| Allen township | 15 | 5,451 | 5,468 | 0% | 503 | 10.8 | Township |
| East Allen township | 16 | 5,392 | 5,014 | 1.56% | 371 | 14.6 | Township |
| Bangor | 17 | 5,108 | 5,186 | -0.39% | 3,424 | 1.5 | Borough |
| Wind Gap | 18 | 3,862 | 2,817 | 7.25% | 2,884 | 1.3 | Borough |
| Pen Argyl | 19 | 3,446 | 3,509 | -0.46% | 2,568 | 1.3 | Borough |
| Lower Mount Bethel township | 20 | 2,898 | 2,913 | -0.03% | 122 | 23.8 | Township |
| Bath | 21 | 2,896 | 2,828 | 0.59% | 3,207 | 0.9 | Borough |
| Walnutport | 22 | 2,090 | 2,073 | 0.19% | 2,779 | 0.8 | Borough |
| Roseto | 23 | 1,552 | 1,579 | -0.45% | 2,467 | 0.6 | Borough |
| Tatamy | 24 | 1,472 | 1,210 | 4.62% | 2,652 | 0.6 | Borough |
| East Bangor | 25 | 1,102 | 1,120 | -0.45% | 1,326 | 0.8 | Borough |
| Stockertown | 26 | 911 | 917 | -0.22% | 939 | 1.0 | Borough |
| Portland | 27 | 479 | 486 | -0.42% | 992 | 0.5 | Borough |
| Chapman | 28 | 219 | 221 | -0.46% | 664 | 0.3 | Borough |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Northampton township is the largest city in Northampton County.
Chapman is the smallest city in Northampton County.
There are 28 cities in Northampton County, Pennsylvania.