Founded in 1845, Polk County is one of 36 counties in the state of Oregon. Historically, Polk County was formed from Yamhill District. The city of Dallas is the county seat. With FIPS code of 53, Polk County has a population of 89,164 and area of 741 square miles (1,919 km2).
List of all cities in Polk County, OR alphabetically
| City/Town | Postal Code | Area Code |
| Dallas, OR | 97338 | 503/971 |
| Falls City, OR | 97344 | 503/971 |
| Grand Ronde, OR | 97347 | 503/971 |
| Independence, OR | 97351 | 503/971 |
| Monmouth, OR | 97361 | 503/971 |
| Rickreall, OR | 97371 | 503/971 |
| Salem, OR | 97304 | 503/971 |