12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mount Pleasant | 1 | 8,131 | 9,255 | -2.69% | 942 | 8.63 | City |
| New London | 2 | 1,842 | 1,911 | -0.75% | 1,699 | 1.08 | City |
| Winfield | 3 | 1,004 | 1,029 | -0.5% | 964 | 1.04 | City |
| Wayland | 4 | 938 | 960 | -0.43% | 882 | 1.06 | City |
| Salem | 5 | 378 | 397 | -1.05% | 604 | 0.63 | City |
| Olds | 6 | 184 | 191 | -0.54% | 540 | 0.34 | City |
| Hillsboro | 7 | 154 | 161 | -0.65% | 266 | 0.58 | City |
| Mount Union | 8 | 152 | 135 | 7.04% | 899 | 0.17 | CDP |
| Swedesburg | 9 | 135 | 175 | 7.14% | 59 | 2.30 | CDP |
| Rome | 10 | 110 | 114 | -0.9% | 887 | 0.12 | City |
| Westwood | 11 | 97 | 104 | -1.02% | 890 | 0.11 | City |
| Trenton | 12 | 87 | 94 | 6.1% | 189 | 0.46 | CDP |
Mount Pleasant is the largest city in Henry County, with a population of 8,131.
Trenton is the smallest city in Henry County.
There are 12 cities in Henry County, Iowa.