Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 2,671 | 2,742 | -0.67% | 750 | 3.6 | City |
| Carthage | 2 | 2,424 | 2,490 | -0.7% | 958 | 2.5 | City |
| Warsaw | 3 | 1,462 | 1,505 | -0.75% | 224 | 6.5 | City |
| La Harpe | 4 | 1,144 | 1,174 | -0.69% | 839 | 1.4 | City |
| Nauvoo | 5 | 917 | 941 | -0.65% | 271 | 3.4 | City |
| Dallas City | 6 | 781 | 807 | -0.89% | 329 | 2.4 | City |
| Augusta | 7 | 540 | 556 | -0.73% | 781 | 0.7 | Village |
| Bowen | 8 | 450 | 461 | -0.66% | 1,051 | 0.4 | Village |
| Plymouth | 9 | 423 | 435 | -0.7% | 749 | 0.6 | Village |
| Elvaston | 10 | 144 | 148 | -0.69% | 180 | 0.8 | Village |
| West Point | 11 | 137 | 141 | -0.73% | 815 | 0.2 | Village |
| Ferris | 12 | 120 | 127 | -1.64% | 61 | 2.0 | Village |
| Pontoosuc | 13 | 99 | 102 | -1% | 70 | 1.4 | Village |
| Basco | 14 | 76 | 79 | -1.3% | 342 | 0.2 | Village |
| Bentley | 15 | 25 | 27 | -3.85% | 175 | 0.1 | Town |
| Niota | 16 | 15 | 85 | 7.14% | 29 | 0.5 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Hamilton is the largest city in Hancock County.
Niota is the smallest city in Hancock County.
There are 16 cities in Hancock County, Illinois.