27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Concord | 1 | 44,909 | 44,040 | 0.31% | 702 | 63.96 | City |
| Hooksett | 2 | 15,434 | 14,917 | 0.4% | 428 | 36.06 | Town |
| Franklin | 3 | 8,770 | 8,745 | -0.11% | 320 | 27.43 | City |
| Bow | 4 | 8,401 | 8,247 | 0.07% | 298 | 28.17 | Town |
| Pembroke | 5 | 7,623 | 7,206 | 0.65% | 337 | 22.64 | Town |
| Henniker | 6 | 6,264 | 6,197 | 0.26% | 142 | 44.12 | Town |
| Hopkinton | 7 | 6,206 | 5,926 | 0.96% | 143 | 43.30 | Town |
| Loudon | 8 | 5,758 | 5,592 | 0.3% | 125 | 46.16 | Town |
| Northfield | 9 | 5,105 | 4,876 | 0.85% | 179 | 28.51 | Town |
| Epsom | 10 | 5,036 | 4,842 | 0.62% | 146 | 34.42 | Town |
| Allenstown | 11 | 4,745 | 4,712 | -0.1% | 232 | 20.46 | Town |
| New London | 12 | 4,475 | 4,402 | 0.13% | 200 | 22.34 | Town |
| Pittsfield | 13 | 4,145 | 4,076 | 0.14% | 173 | 24.02 | Town |
| Boscawen | 14 | 4,113 | 4,005 | 1.03% | 165 | 24.89 | Town |
| Dunbarton | 15 | 3,204 | 3,013 | 1.3% | 104 | 30.86 | Town |
| Warner | 16 | 2,979 | 2,931 | 0.27% | 54 | 55.23 | Town |
| Chichester | 17 | 2,792 | 2,670 | 0.36% | 132 | 21.19 | Town |
| Canterbury | 18 | 2,471 | 2,387 | 0.28% | 56 | 43.88 | Town |
| Andover | 19 | 2,438 | 2,402 | 0.16% | 61 | 40.15 | Town |
| Newbury | 20 | 2,321 | 2,179 | 1.13% | 65 | 35.84 | Town |
| Sutton | 21 | 2,057 | 1,984 | 0.39% | 48 | 42.55 | Town |
| Webster | 22 | 1,984 | 1,920 | 0.4% | 70 | 28.21 | Town |
| Bradford | 23 | 1,739 | 1,661 | 0.64% | 49 | 35.24 | Town |
| Salisbury | 24 | 1,523 | 1,427 | 0.86% | 38 | 39.58 | Town |
| Wilmot | 25 | 1,520 | 1,411 | 1.81% | 52 | 29.41 | Town |
| Danbury | 26 | 1,324 | 1,255 | 1.07% | 35 | 37.73 | Town |
| Hill | 27 | 1,055 | 1,015 | 0.57% | 40 | 26.55 | Town |
Concord is the largest city in Merrimack County, with a population of 44,909.
Hill is the smallest city in Merrimack County.
There are 27 cities in Merrimack County, New Hampshire.