12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Harlan | 1 | 4,886 | 4,898 | -0.04% | 1,105 | 4.42 | City |
| Elk Horn | 2 | 651 | 601 | 1.56% | 888 | 0.73 | City |
| Earling | 3 | 392 | 394 | 0% | 624 | 0.63 | City |
| Irwin | 4 | 318 | 322 | -0.31% | 543 | 0.59 | City |
| Defiance | 5 | 243 | 247 | -0.41% | 651 | 0.37 | City |
| Panama | 6 | 237 | 237 | 0% | 817 | 0.29 | City |
| Portsmouth | 7 | 191 | 186 | 0.53% | 622 | 0.31 | City |
| Westphalia | 8 | 136 | 131 | 0.74% | 1,388 | 0.10 | City |
| Tennant | 9 | 85 | 79 | 1.19% | 118 | 0.72 | City |
| Kirkman | 10 | 61 | 58 | 1.67% | 237 | 0.26 | City |
| Corley | 11 | 8 | 7 | 14.29% | 133 | 0.06 | CDP |
| Jacksonville | 12 | 5 | 10 | 0% | 51 | 0.10 | CDP |
Harlan is the largest city in Shelby County, with a population of 4,886.
Jacksonville is the smallest city in Shelby County.
There are 12 cities in Shelby County, Iowa.