10 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mason City | 1 | 26,782 | 27,280 | -0.31% | 947 | 28 | City |
| Clear Lake | 2 | 7,570 | 7,666 | -0.21% | 702 | 11 | City |
| Rockwell | 3 | 1,031 | 1,069 | -0.58% | 347 | 3 | City |
| Ventura | 4 | 696 | 711 | -0.29% | 392 | 2 | City |
| Thornton | 5 | 389 | 404 | -0.51% | 313 | 1 | City |
| Plymouth | 6 | 362 | 379 | -0.82% | 821 | 0 | City |
| Meservey | 7 | 208 | 219 | -0.95% | 139 | 1 | City |
| Rock Falls | 8 | 140 | 149 | -0.71% | 676 | 0 | City |
| Swaledale | 9 | 133 | 142 | -0.75% | 534 | 0 | City |
| Dougherty | 10 | 60 | 63 | 0% | 107 | 1 | City |
Mason City is the largest city in Cerro Gordo County, with a population of 26,782.
Dougherty is the smallest city in Cerro Gordo County, with a population of 60.
There are 10 cities in Cerro Gordo County, Iowa.