18 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Laconia | 1 | 17,473 | 16,890 | 0.94% | 881 | 20 | City |
| Laconia | 2 | 17,415 | 16,890 | 0.61% | 878 | 20 | City |
| Gilford | 3 | 7,907 | 7,708 | 0.27% | 204 | 39 | Town |
| Belmont | 4 | 7,444 | 7,312 | 0.22% | 249 | 30 | Town |
| Meredith | 5 | 6,854 | 6,671 | 0.37% | 171 | 40 | Town |
| Alton | 6 | 6,067 | 5,896 | 0.26% | 95 | 64 | Town |
| Barnstead | 7 | 5,053 | 4,924 | 0.34% | 117 | 43 | Town |
| Tilton | 8 | 4,105 | 3,967 | -0.27% | 368 | 11 | Town |
| Gilmanton | 9 | 4,073 | 3,955 | 0.02% | 70 | 58 | Town |
| Sanbornton | 10 | 3,048 | 3,033 | -0.29% | 64 | 47 | Town |
| Tilton Northfield | 11 | 3,025 | 2,795 | -0.1% | 965 | 3 | CDP |
| Meredith | 12 | 3,018 | 2,651 | 2.97% | 1,035 | 3 | CDP |
| New Hampton | 13 | 2,422 | 2,378 | -0.12% | 66 | 37 | Town |
| Belmont | 14 | 1,240 | 1,272 | -0.32% | 986 | 1 | CDP |
| Center Harbor | 15 | 1,049 | 1,040 | 0.19% | 79 | 13 | Town |
| Suissevale | 16 | 445 | 386 | 3.01% | 379 | 1 | CDP |
| New Hampton | 17 | 317 | 326 | -0.94% | 249 | 1 | CDP |
| Alton | 18 | 87 | 170 | -24.35% | 186 | 0 | CDP |
Laconia is the largest city in Belknap County, with a population of 17,473.
Alton is the smallest city in Belknap County, with a population of 87.
There are 18 cities in Belknap County, New Hampshire.