39 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Concord | 1 | 45,021 | 44,040 | 0.44% | 704 | 63.96 | City |
| Concord | 2 | 44,909 | 44,040 | 0.31% | 702 | 63.96 | City |
| Hooksett | 3 | 15,434 | 14,917 | 0.4% | 428 | 36.06 | Town |
| Franklin | 4 | 8,820 | 8,745 | 0.17% | 322 | 27.43 | City |
| Franklin | 5 | 8,770 | 8,745 | -0.11% | 320 | 27.43 | City |
| Bow | 6 | 8,401 | 8,247 | 0.07% | 298 | 28.17 | Town |
| Pembroke | 7 | 7,623 | 7,206 | 0.65% | 337 | 22.64 | Town |
| Henniker | 8 | 6,264 | 6,197 | 0.26% | 142 | 44.12 | Town |
| Hopkinton | 9 | 6,206 | 5,926 | 0.96% | 143 | 43.30 | Town |
| Loudon | 10 | 5,758 | 5,592 | 0.3% | 125 | 46.16 | Town |
| Hooksett | 11 | 5,548 | 5,517 | 1.7% | 1,028 | 5.40 | CDP |
| Suncook | 12 | 5,199 | 4,975 | -0.23% | 1,397 | 3.72 | CDP |
| Northfield | 13 | 5,105 | 4,876 | 0.85% | 179 | 28.51 | Town |
| Epsom | 14 | 5,036 | 4,842 | 0.62% | 146 | 34.42 | Town |
| Allenstown | 15 | 4,745 | 4,712 | -0.11% | 232 | 20.46 | Town |
| New London | 16 | 4,475 | 4,402 | 0.13% | 200 | 22.34 | Town |
| Pittsfield | 17 | 4,145 | 4,076 | 0.14% | 173 | 24.02 | Town |
| Boscawen | 18 | 4,113 | 4,005 | 1.03% | 165 | 24.89 | Town |
| Dunbarton | 19 | 3,204 | 3,013 | 1.3% | 104 | 30.86 | Town |
| Henniker | 20 | 2,990 | 2,566 | 2.86% | 2,112 | 1.42 | CDP |
| Warner | 21 | 2,979 | 2,931 | 0.27% | 54 | 55.23 | Town |
| Chichester | 22 | 2,792 | 2,670 | 0.36% | 132 | 21.19 | Town |
| Canterbury | 23 | 2,471 | 2,387 | 0.28% | 56 | 43.88 | Town |
| Andover | 24 | 2,438 | 2,402 | 0.16% | 61 | 40.15 | Town |
| Newbury | 25 | 2,321 | 2,179 | 1.13% | 65 | 35.84 | Town |
| Sutton | 26 | 2,057 | 1,984 | 0.39% | 48 | 42.55 | Town |
| Webster | 27 | 1,984 | 1,920 | 0.4% | 70 | 28.21 | Town |
| Pittsfield | 28 | 1,836 | 1,464 | 0.93% | 1,092 | 1.68 | CDP |
| Bradford | 29 | 1,739 | 1,661 | 0.64% | 49 | 35.24 | Town |
| Salisbury | 30 | 1,523 | 1,427 | 0.86% | 38 | 39.58 | Town |
| Wilmot | 31 | 1,520 | 1,411 | 1.81% | 52 | 29.41 | Town |
| Danbury | 32 | 1,324 | 1,255 | 1.07% | 35 | 37.73 | Town |
| New London | 33 | 1,321 | 1,364 | -0.53% | 1,189 | 1.11 | CDP |
| Contoocook | 34 | 1,258 | 1,353 | -0.94% | 547 | 2.30 | CDP |
| Hill | 35 | 1,055 | 1,015 | 0.57% | 40 | 26.55 | Town |
| Loudon | 36 | 678 | 830 | 1.19% | 375 | 1.81 | CDP |
| Warner | 37 | 420 | 638 | -0.47% | 525 | 0.80 | CDP |
| Bradford | 38 | 395 | 306 | 0.77% | 497 | 0.79 | CDP |
| Blodgett Landing | 39 | 104 | 88 | 0.97% | 357 | 0.29 | CDP |
Concord is the largest city in Merrimack County, with a population of 45,021.
Blodgett Landing is the smallest city in Merrimack County, with a population of 104.
There are 39 cities in Merrimack County, New Hampshire.