34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Derry | 1 | 33,908 | 34,307 | -0.5% | 956 | 35.47 | Town |
| Salem | 2 | 33,283 | 30,281 | 2.67% | 1,340 | 24.84 | Town |
| Londonderry | 3 | 27,004 | 25,870 | 0.55% | 643 | 42 | Town |
| Portsmouth | 4 | 22,827 | 21,992 | 0.21% | 1,458 | 15.66 | City |
| Hampton | 5 | 16,298 | 16,234 | -0.39% | 1,262 | 12.91 | Town |
| Exeter | 6 | 16,098 | 16,043 | -0.23% | 821 | 19.60 | Town |
| Windham | 7 | 16,086 | 15,836 | 0% | 601 | 26.74 | Town |
| Raymond | 8 | 10,942 | 10,702 | -0.14% | 380 | 28.82 | Town |
| Newmarket | 9 | 9,571 | 9,424 | 0.48% | 760 | 12.59 | Town |
| Hampstead | 10 | 9,113 | 9,004 | -0.09% | 679 | 13.42 | Town |
| Seabrook | 11 | 8,355 | 8,407 | -0.35% | 931 | 8.98 | Town |
| Epping | 12 | 7,783 | 7,151 | 1.47% | 299 | 26.03 | Town |
| Plaistow | 13 | 7,764 | 7,833 | -0.44% | 733 | 10.59 | Town |
| Stratham | 14 | 7,672 | 7,695 | -0.57% | 506 | 15.15 | Town |
| Atkinson | 15 | 7,410 | 7,097 | 0.39% | 664 | 11.16 | Town |
| Sandown | 16 | 6,722 | 6,551 | 0.48% | 482 | 13.93 | Town |
| Auburn | 17 | 6,269 | 5,958 | 0.79% | 247 | 25.35 | Town |
| Kingston | 18 | 6,246 | 6,202 | -0.43% | 316 | 19.79 | Town |
| Rye | 19 | 5,567 | 5,544 | -0.34% | 440 | 12.64 | Town |
| Nottingham | 20 | 5,443 | 5,241 | 0.41% | 117 | 46.50 | Town |
| Chester | 21 | 5,294 | 5,233 | -0.11% | 204 | 26.01 | Town |
| Deerfield | 22 | 4,971 | 4,864 | 0.08% | 98 | 50.76 | Town |
| Fremont | 23 | 4,897 | 4,745 | 0.47% | 285 | 17.17 | Town |
| Brentwood | 24 | 4,864 | 4,499 | 1.91% | 289 | 16.82 | Town |
| Newton | 25 | 4,836 | 4,819 | 0.06% | 493 | 9.81 | Town |
| Northwood | 26 | 4,712 | 4,642 | 0.26% | 167 | 28.16 | Town |
| Danville | 27 | 4,678 | 4,415 | 1.08% | 402 | 11.65 | Town |
| North Hampton | 28 | 4,495 | 4,535 | -0.44% | 324 | 13.89 | Town |
| Candia | 29 | 4,229 | 4,020 | 0.62% | 139 | 30.34 | Town |
| Greenland | 30 | 4,089 | 4,066 | -0.22% | 390 | 10.48 | Town |
| East Kingston | 31 | 2,420 | 2,439 | -0.37% | 244 | 9.92 | Town |
| Hampton Falls | 32 | 2,371 | 2,406 | -0.59% | 194 | 12.22 | Town |
| Kensington | 33 | 2,096 | 2,095 | 0.05% | 175 | 11.97 | Town |
| Newfields | 34 | 1,775 | 1,774 | 0% | 250 | 7.09 | Town |
Derry is the largest city in Rockingham County, with a population of 33,908.
Newfields is the smallest city in Rockingham County.
There are 34 cities in Rockingham County, New Hampshire.