38 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kewanee | 1 | 11,985 | 12,468 | -0.66% | 1,816 | 7 | City |
| Kewanee | 2 | 9,409 | 9,765 | -0.53% | 260 | 36 | Township |
| Geneseo | 3 | 7,469 | 7,554 | -0.2% | 206 | 36 | Township |
| Colona | 4 | 6,563 | 6,698 | -0.18% | 227 | 29 | Township |
| Geneseo | 5 | 6,483 | 6,543 | -0.15% | 1,376 | 5 | City |
| Colona | 6 | 4,921 | 5,037 | -0.38% | 1,289 | 4 | City |
| Wethersfield | 7 | 3,672 | 3,797 | -0.46% | 103 | 36 | Township |
| Western | 8 | 2,838 | 2,926 | -0.42% | 80 | 35 | Township |
| Galva | 9 | 2,619 | 2,708 | -0.42% | 76 | 34 | Township |
| Galva | 10 | 2,364 | 2,459 | -0.67% | 855 | 3 | City |
| Cambridge | 11 | 2,345 | 2,423 | -0.47% | 64 | 37 | Township |
| Hanna | 12 | 2,322 | 2,391 | -0.43% | 121 | 19 | Township |
| Cambridge | 13 | 2,009 | 2,084 | -0.59% | 1,009 | 2 | Village |
| Orion | 14 | 1,694 | 1,753 | -0.59% | 1,812 | 1 | Village |
| Phenix | 15 | 1,646 | 1,691 | -0.3% | 50 | 33 | Township |
| Atkinson | 16 | 1,188 | 1,236 | -0.67% | 34 | 35 | Township |
| Oxford | 17 | 1,116 | 1,154 | -0.45% | 31 | 36 | Township |
| Orion | 18 | 1,111 | 1,144 | -0.27% | 30 | 36 | Township |
| Annawan | 19 | 1,076 | 1,118 | -0.55% | 30 | 36 | Township |
| Atkinson | 20 | 917 | 955 | -0.65% | 481 | 2 | Town |
| Andover | 21 | 860 | 888 | -0.35% | 24 | 37 | Township |
| Annawan | 22 | 848 | 884 | -0.7% | 396 | 2 | Town |
| Clover | 23 | 818 | 848 | -0.49% | 23 | 35 | Township |
| Lynn | 24 | 764 | 788 | -0.39% | 21 | 36 | Township |
| Woodhull | 25 | 723 | 753 | -0.69% | 823 | 1 | Village |
| Alpha | 26 | 644 | 670 | -0.62% | 2,071 | 0 | Village |
| Edford | 27 | 636 | 652 | -0.31% | 23 | 27 | Township |
| Andover | 28 | 531 | 555 | -0.75% | 536 | 1 | Village |
| Yorktown | 29 | 425 | 438 | -0.23% | 12 | 36 | Township |
| Osco | 30 | 411 | 426 | -0.48% | 11 | 36 | Township |
| Weller | 31 | 388 | 396 | -0.26% | 11 | 34 | Township |
| Munson | 32 | 345 | 358 | -0.86% | 10 | 36 | Township |
| Cornwall | 33 | 251 | 258 | -0.4% | 7 | 36 | Township |
| Burns | 34 | 232 | 238 | -0.43% | 6 | 36 | Township |
| Hooppole | 35 | 170 | 179 | -0.58% | 457 | 0 | Village |
| Alba | 36 | 165 | 171 | -0.6% | 5 | 36 | Township |
| Cleveland | 37 | 150 | 159 | -0.66% | 510 | 0 | Village |
| Bishop Hill | 38 | 111 | 113 | 0% | 208 | 1 | Village |
Kewanee is the largest city in Henry County, with a population of 11,985.
Bishop Hill is the smallest city in Henry County, with a population of 111.
There are 38 cities in Henry County, Illinois.