4 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Dallas | 1 | 18,366 | 17,000 | 1.26% | 3,740 | 5 | City |
| Monmouth | 2 | 11,904 | 11,144 | 1.08% | 5,317 | 2 | City |
| Independence | 3 | 10,442 | 10,001 | 0.71% | 3,489 | 3 | City |
| Falls City | 4 | 1,057 | 1,056 | 0% | 879 | 1 | City |
Dallas is the largest city in Polk County, with a population of 18,366.
Falls City is the smallest city in Polk County, with a population of 1,057.
There are 4 cities in Polk County, Oregon.