41 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Montebello | 1 | 3,168 | 3,329 | -1% | 86 | 37 | Township |
| West Point | 2 | 3,052 | 3,198 | -0.59% | 85 | 36 | Township |
| Carthage | 3 | 2,820 | 2,976 | -1.16% | 70 | 40 | Township |
| Hamilton | 4 | 2,621 | 2,743 | -0.76% | 736 | 4 | City |
| Carthage | 5 | 2,393 | 2,506 | -0.79% | 946 | 3 | City |
| Warsaw | 6 | 1,431 | 1,506 | -0.83% | 219 | 7 | City |
| Warsaw | 7 | 1,420 | 1,506 | -1.25% | 218 | 7 | Township |
| La Harpe | 8 | 1,313 | 1,380 | -0.98% | 35 | 37 | Township |
| La Harpe | 9 | 1,119 | 1,173 | -0.8% | 820 | 1 | City |
| Nauvoo | 10 | 896 | 943 | -0.99% | 230 | 4 | Township |
| Nauvoo | 11 | 895 | 939 | -0.78% | 264 | 3 | City |
| Dallas City | 12 | 822 | 871 | -1.2% | 53 | 15 | Township |
| Dallas City | 13 | 763 | 808 | -0.91% | 321 | 2 | City |
| Augusta | 14 | 667 | 708 | -1.33% | 18 | 38 | Township |
| Chili | 15 | 582 | 612 | -1.02% | 15 | 38 | Township |
| St. Mary | 16 | 533 | 560 | -0.93% | 14 | 37 | Township |
| Augusta | 17 | 530 | 556 | -0.75% | 767 | 1 | Village |
| Bowen | 18 | 440 | 461 | -0.68% | 1,028 | 0 | Village |
| Sonora | 19 | 424 | 446 | -0.93% | 12 | 36 | Township |
| Plymouth | 20 | 414 | 434 | -0.72% | 733 | 1 | Village |
| Appanoose | 21 | 411 | 432 | -0.96% | 16 | 26 | Township |
| Prairie | 22 | 365 | 386 | -1.08% | 11 | 33 | Township |
| Pontoosuc | 23 | 318 | 339 | -1.55% | 17 | 18 | Township |
| Bear Creek | 24 | 305 | 320 | -0.65% | 8 | 36 | Township |
| Rock Creek | 25 | 300 | 317 | -0.99% | 8 | 36 | Township |
| Harmony | 26 | 290 | 304 | -0.68% | 8 | 38 | Township |
| St. Albans | 27 | 290 | 308 | -1.36% | 8 | 36 | Township |
| Walker | 28 | 272 | 288 | -1.09% | 7 | 38 | Township |
| Rocky Run-Wilcox | 29 | 270 | 290 | -1.82% | 5 | 57 | Township |
| Durham | 30 | 241 | 254 | -0.82% | 7 | 37 | Township |
| Hancock | 31 | 238 | 251 | -1.24% | 6 | 38 | Township |
| Pilot Grove | 32 | 232 | 247 | -1.28% | 6 | 37 | Township |
| Fountain Green | 33 | 229 | 244 | -1.29% | 6 | 38 | Township |
| Wythe | 34 | 228 | 247 | -2.15% | 6 | 38 | Township |
| Hamilton | 35 | 177 | 183 | -0.56% | 5 | 36 | Township |
| Elvaston | 36 | 143 | 149 | -0.69% | 179 | 1 | Village |
| West Point | 37 | 133 | 142 | -0.75% | 792 | 0 | Village |
| Ferris | 38 | 117 | 126 | -0.85% | 59 | 2 | Village |
| Pontoosuc | 39 | 96 | 101 | -1.03% | 68 | 1 | Village |
| Basco | 40 | 76 | 79 | 0% | 342 | 0 | Village |
| Bentley | 41 | 25 | 27 | 0% | 175 | 0 | Town |
Montebello is the largest city in Hancock County, with a population of 3,168.
Bentley is the smallest city in Hancock County, with a population of 25.
There are 41 cities in Hancock County, Illinois.