17 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Des Moines | 1 | 212,759 | 213,769 | -0.08% | 2,413 | 88 | City |
| Ankeny | 2 | 80,809 | 68,562 | 2.59% | 2,475 | 33 | City |
| West Des Moines | 3 | 76,036 | 68,920 | 1.58% | 1,601 | 48 | City |
| Urbandale | 4 | 48,850 | 45,577 | 1.13% | 2,166 | 23 | City |
| Johnston | 5 | 25,537 | 23,992 | 1.02% | 1,310 | 19 | City |
| Altoona | 6 | 24,021 | 19,751 | 3.05% | 1,796 | 13 | City |
| Clive | 7 | 19,926 | 18,672 | 1.06% | 2,603 | 8 | City |
| Grimes | 8 | 18,040 | 15,718 | 2.19% | 1,303 | 14 | City |
| Pleasant Hill | 9 | 12,830 | 10,165 | 3.58% | 1,187 | 11 | City |
| Bondurant | 10 | 10,533 | 7,467 | 5.1% | 946 | 11 | City |
| Polk City | 11 | 6,845 | 5,599 | 3.13% | 1,215 | 6 | City |
| Windsor Heights | 12 | 5,041 | 5,236 | -0.63% | 3,515 | 1 | City |
| Mitchellville | 13 | 2,785 | 2,487 | 1.83% | 995 | 3 | City |
| Elkhart | 14 | 1,173 | 891 | 4.17% | 622 | 2 | City |
| Runnells | 15 | 469 | 462 | 0.21% | 816 | 1 | City |
| Alleman | 16 | 442 | 432 | 0.45% | 150 | 3 | City |
| Sheldahl | 17 | 319 | 298 | 1.27% | 395 | 1 | City |
Des Moines is the largest city in Polk County, with a population of 212,759.
Sheldahl is the smallest city in Polk County, with a population of 319.
There are 17 cities in Polk County, Iowa.