| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Crook County | 1 | 12.73% | 28,102 | 24,929 |
| Deschutes County | 2 | 6.57% | 212,573 | 199,464 |
| Sherman County | 3 | 4.7% | 1,959 | 1,871 |
| Jefferson County | 4 | 4.61% | 25,714 | 24,581 |
| Wallowa County | 5 | 4.27% | 7,722 | 7,406 |
| Linn County | 6 | 3.31% | 133,244 | 128,981 |
| Columbia County | 7 | 3.23% | 54,426 | 52,724 |
| Benton County | 8 | 2.73% | 97,817 | 95,214 |
| Polk County | 9 | 2.58% | 90,229 | 87,956 |
| Malheur County | 10 | 2.45% | 32,416 | 31,642 |
| Gilliam County | 11 | 2.28% | 2,062 | 2,016 |
| Douglas County | 12 | 1.28% | 112,725 | 111,295 |
| Yamhill County | 13 | 1.17% | 109,208 | 107,945 |
| Lincoln County | 14 | 0.89% | 50,959 | 50,510 |
| Morrow County | 15 | 0.83% | 12,322 | 12,221 |
| Baker County | 16 | 0.78% | 16,862 | 16,731 |
| Clackamas County | 17 | 0.19% | 423,283 | 422,468 |
| Marion County | 18 | 0.13% | 346,785 | 346,350 |
| Klamath County | 19 | 0.11% | 69,629 | 69,553 |
| Josephine County | 20 | -0.42% | 87,863 | 88,238 |
| Lake County | 21 | -0.48% | 8,133 | 8,172 |
| Umatilla County | 22 | -0.59% | 79,637 | 80,108 |
| Grant County | 23 | -0.62% | 7,195 | 7,240 |
| Washington County | 24 | -0.78% | 596,423 | 601,130 |
| Tillamook County | 25 | -0.92% | 27,209 | 27,461 |
| Lane County | 26 | -1.08% | 379,181 | 383,308 |
| Wheeler County | 27 | -1.1% | 1,438 | 1,454 |
| Jackson County | 28 | -2.08% | 218,966 | 223,620 |
| Union County | 29 | -2.56% | 25,502 | 26,173 |
| Clatsop County | 30 | -2.82% | 40,002 | 41,162 |
| Wasco County | 31 | -2.82% | 25,889 | 26,640 |
| Hood River County | 32 | -3.33% | 23,165 | 23,962 |
| Harney County | 33 | -3.34% | 7,256 | 7,507 |
| Coos County | 34 | -3.37% | 62,790 | 64,979 |
| Curry County | 35 | -3.64% | 22,662 | 23,519 |
| Multnomah County | 36 | -4.48% | 779,968 | 816,514 |
Oregon's counties show varied growth patterns from 2020 to 2025. Crook County leads with 12.73% annualized growth, followed by Deschutes County (6.57%) and Sherman County (4.7%). The largest counties are Multnomah County (779,968), Washington County (596,423), and Clackamas County (423,283). Of the 36 counties in Oregon, 19 are growing while 17 have experienced population decline. Overall, counties averaged 0.57% annualized growth, with total population growing by -0.56% annually.