12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mount Pleasant | 1 | 8,319 | 9,267 | -2.23% | 964 | 9 | City |
| New London | 2 | 1,838 | 1,910 | -0.81% | 1,696 | 1 | City |
| Winfield | 3 | 1,000 | 1,030 | -0.6% | 961 | 1 | City |
| Wayland | 4 | 928 | 960 | -0.75% | 872 | 1 | City |
| Salem | 5 | 376 | 395 | -1.05% | 601 | 1 | City |
| Olds | 6 | 172 | 180 | -1.15% | 504 | 0 | City |
| Hillsboro | 7 | 157 | 162 | -0.63% | 271 | 1 | City |
| Mount Union | 8 | 152 | 135 | 7.04% | 899 | 0 | CDP |
| Swedesburg | 9 | 135 | 175 | 7.14% | 59 | 2 | CDP |
| Rome | 10 | 111 | 115 | -0.89% | 895 | 0 | City |
| Westwood | 11 | 94 | 101 | -2.08% | 862 | 0 | City |
| Trenton | 12 | 87 | 94 | 6.1% | 189 | 0 | CDP |
Mount Pleasant is the largest city in Henry County, with a population of 8,319.
Trenton is the smallest city in Henry County, with a population of 87.
There are 12 cities in Henry County, Iowa.