27 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Concord | 1 | 44,862 | 44,040 | 0.21% | 701 | 64 | City |
| Hooksett | 2 | 15,613 | 14,907 | 0.76% | 433 | 36 | Town |
| Franklin | 3 | 8,857 | 8,748 | 0.19% | 323 | 27 | City |
| Bow | 4 | 8,423 | 8,246 | 0.15% | 299 | 28 | Town |
| Pembroke | 5 | 7,667 | 7,206 | 0.66% | 339 | 23 | Town |
| Henniker | 6 | 6,307 | 6,190 | 0.32% | 143 | 44 | Town |
| Hopkinton | 7 | 6,266 | 5,929 | 0.97% | 145 | 43 | Town |
| Loudon | 8 | 5,770 | 5,591 | 0.26% | 125 | 46 | Town |
| Northfield | 9 | 5,162 | 4,877 | 0.94% | 181 | 29 | Town |
| Epsom | 10 | 5,096 | 4,839 | 0.75% | 148 | 34 | Town |
| Allenstown | 11 | 4,779 | 4,712 | 0.15% | 234 | 20 | Town |
| New London | 12 | 4,480 | 4,409 | 0.22% | 201 | 22 | Town |
| Boscawen | 13 | 4,269 | 4,005 | 1.38% | 172 | 25 | Town |
| Pittsfield | 14 | 4,164 | 4,078 | 0.26% | 173 | 24 | Town |
| Dunbarton | 15 | 3,316 | 3,013 | 2% | 107 | 31 | Town |
| Warner | 16 | 2,990 | 2,936 | 0.34% | 54 | 55 | Town |
| Chichester | 17 | 2,893 | 2,669 | 1.44% | 137 | 21 | Town |
| Canterbury | 18 | 2,493 | 2,387 | 0.52% | 57 | 44 | Town |
| Andover | 19 | 2,486 | 2,404 | 0.73% | 62 | 40 | Town |
| Newbury | 20 | 2,348 | 2,176 | 1.21% | 66 | 36 | Town |
| Sutton | 21 | 2,125 | 1,984 | 1.38% | 50 | 43 | Town |
| Webster | 22 | 2,003 | 1,923 | 0.6% | 71 | 28 | Town |
| Bradford | 23 | 1,728 | 1,661 | 0.17% | 49 | 35 | Town |
| Salisbury | 24 | 1,524 | 1,427 | 0.66% | 39 | 40 | Town |
| Wilmot | 25 | 1,485 | 1,409 | 0.47% | 50 | 29 | Town |
| Danbury | 26 | 1,317 | 1,258 | 0.53% | 35 | 38 | Town |
| Hill | 27 | 1,066 | 1,015 | 0.76% | 40 | 27 | Town |
Concord is the largest city in Merrimack County, with a population of 44,862.
Hill is the smallest city in Merrimack County, with a population of 1,066.
There are 27 cities in Merrimack County, New Hampshire.