| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Des Moines | 1 | 211,734 | 213,682 | -0.17% | 2,402 | 88 | City |
| Ankeny | 2 | 79,782 | 68,659 | 2.5% | 2,443 | 33 | City |
| West Des Moines | 3 | 75,503 | 68,962 | 1.72% | 1,589 | 48 | City |
| Urbandale | 4 | 49,154 | 45,588 | 1.2% | 2,180 | 23 | City |
| Johnston | 5 | 25,303 | 23,984 | 0.95% | 1,298 | 19 | City |
| Altoona | 6 | 23,486 | 19,742 | 3.03% | 1,756 | 13 | City |
| Clive | 7 | 20,106 | 18,689 | 1.23% | 2,626 | 8 | City |
| Grimes | 8 | 17,780 | 15,719 | 2.15% | 1,284 | 14 | City |
| Pleasant Hill | 9 | 11,472 | 10,150 | 2.07% | 1,061 | 11 | City |
| Bondurant | 10 | 10,117 | 7,475 | 4.87% | 909 | 11 | City |
| Polk City | 11 | 6,855 | 5,610 | 3.39% | 1,216 | 6 | City |
| Windsor Heights | 12 | 5,024 | 5,235 | -0.69% | 3,503 | 1 | City |
| Mitchellville | 13 | 2,719 | 2,486 | 1.8% | 971 | 3 | City |
| Elkhart | 14 | 1,143 | 897 | 4.19% | 606 | 2 | City |
| Runnells | 15 | 461 | 460 | 0% | 802 | 1 | City |
| Alleman | 16 | 441 | 431 | 0.23% | 150 | 3 | City |
| Sheldahl | 17 | 308 | 299 | 0.65% | 382 | 1 | City |
Des Moines is the largest city in Polk County, with a population of 211,734.
Sheldahl is the smallest city in Polk County, with a population of 308.
There are 17 cities in Polk County, Iowa.