18 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Laconia | 1 | 17,314 | 16,883 | 0.5% | 873 | 19.84 | City |
| Laconia | 2 | 17,290 | 16,883 | 0.43% | 872 | 19.84 | City |
| Gilford | 3 | 7,921 | 7,711 | 0.29% | 204 | 38.79 | Town |
| Belmont | 4 | 7,442 | 7,317 | 0.11% | 249 | 29.94 | Town |
| Meredith | 5 | 6,887 | 6,672 | 0.79% | 172 | 40.08 | Town |
| Alton | 6 | 6,086 | 5,898 | 0.36% | 96 | 63.70 | Town |
| Barnstead | 7 | 5,074 | 4,923 | 0.52% | 118 | 43.06 | Town |
| Tilton | 8 | 4,216 | 3,967 | 1.05% | 378 | 11.14 | Town |
| Gilmanton | 9 | 4,183 | 3,955 | 1.33% | 72 | 57.90 | Town |
| Sanbornton | 10 | 3,080 | 3,034 | 0.23% | 65 | 47.37 | Town |
| Tilton Northfield | 11 | 3,025 | 2,795 | -0.1% | 965 | 3.13 | CDP |
| Meredith | 12 | 3,018 | 2,651 | 2.97% | 1,035 | 2.92 | CDP |
| New Hampton | 13 | 2,432 | 2,376 | 0.08% | 66 | 36.77 | Town |
| Belmont | 14 | 1,240 | 1,272 | -0.32% | 986 | 1.26 | CDP |
| Center Harbor | 15 | 1,060 | 1,040 | 0.66% | 80 | 13.27 | Town |
| Suissevale | 16 | 445 | 386 | 3.01% | 379 | 1.17 | CDP |
| New Hampton | 17 | 317 | 326 | -0.94% | 249 | 1.27 | CDP |
| Alton | 18 | 87 | 170 | -24.35% | 186 | 0.47 | CDP |
Laconia is the largest city in Belknap County, with a population of 17,314.
Alton is the smallest city in Belknap County, with a population of 87.
There are 18 cities in Belknap County, New Hampshire.