(Links below lead to Quick Facts for Oregon Counties: People, Business & Geography at U.S. Census Bureau.)
| Area | 7/1/2008 | 7/1/2007 | 7/1/2006 | 7/1/2005 | 7/1/2004 | 7/1/2003 | 7/1/2002 | 7/1/2001 | 7/1/2000 | Census 2000 |
| Oregon | 3,790,060 | 3,735,549 | 3,680,968 | 3,621,939 | 3,576,262 | 3,551,877 | 3,517,982 | 3,470,716 | 3,430,828 | 3,421,399 |
|---|---|---|---|---|---|---|---|---|---|---|
| Baker County | 15,983 | 15,915 | 15,916 | 16,008 | 16,205 | 16,270 | 16,351 | 16,609 | 16,717 | 16,741 |
| Benton County | 81,859 | 81,151 | 80,110 | 79,452 | 78,949 | 79,398 | 79,585 | 78,149 | 78,187 | 78,153 |
| Clackamas County | 380,576 | 375,107 | 370,591 | 365,612 | 360,831 | 355,791 | 351,661 | 344,837 | 339,512 | 338,391 |
| Clatsop County | 37,404 | 37,305 | 36,930 | 36,489 | 36,082 | 35,788 | 35,607 | 35,538 | 35,568 | 35,630 |
| Columbia County | 49,408 | 48,914 | 48,212 | 47,008 | 46,241 | 45,675 | 45,155 | 44,233 | 43,657 | 43,560 |
| Coos County | 63,453 | 63,447 | 63,675 | 63,685 | 63,087 | 62,543 | 62,250 | 62,169 | 62,671 | 62,779 |
| Crook County | 23,023 | 22,857 | 22,499 | 21,685 | 21,171 | 20,401 | 20,065 | 19,876 | 19,321 | 19,182 |
| Curry County | 21,523 | 21,751 | 21,946 | 22,082 | 21,938 | 21,500 | 21,381 | 21,100 | 21,105 | 21,137 |
| Deschutes County | 158,456 | 153,799 | 148,827 | 140,942 | 134,056 | 129,292 | 125,440 | 120,645 | 116,613 | 115,367 |
| Douglas County | 104,059 | 104,000 | 103,777 | 102,878 | 102,052 | 101,333 | 100,595 | 100,077 | 100,426 | 100,399 |
| Gilliam County | 1,747 | 1,686 | 1,707 | 1,741 | 1,763 | 1,750 | 1,829 | 1,876 | 1,908 | 1,915 |
| Grant County | 6,916 | 6,896 | 7,025 | 7,101 | 7,192 | 7,302 | 7,333 | 7,448 | 7,903 | 7,935 |
| Harney County | 6,747 | 6,768 | 6,793 | 6,805 | 6,977 | 7,096 | 7,234 | 7,384 | 7,629 | 7,609 |
| Hood River County | 21,536 | 21,200 | 21,120 | 20,984 | 20,812 | 20,604 | 20,609 | 20,394 | 20,467 | 20,411 |
| Jackson County | 201,138 | 199,003 | 196,502 | 194,268 | 191,816 | 189,533 | 186,592 | 183,797 | 181,788 | 181,269 |
| Jefferson County | 20,512 | 20,628 | 20,076 | 19,705 | 19,602 | 19,651 | 19,574 | 19,465 | 19,103 | 19,009 |
| Josephine County | 81,618 | 80,928 | 80,713 | 79,877 | 79,108 | 78,301 | 77,421 | 76,307 | 75,842 | 75,726 |
| Klamath County | 66,425 | 66,408 | 65,896 | 65,365 | 64,725 | 64,532 | 64,087 | 64,102 | 63,885 | 63,775 |
| Lake County | 7,239 | 7,247 | 7,260 | 7,086 | 7,195 | 7,285 | 7,326 | 7,428 | 7,410 | 7,422 |
| Lane County | 346,560 | 342,781 | 339,422 | 335,422 | 331,990 | 330,504 | 327,402 | 324,822 | 323,485 | 322,959 |
| Lincoln County | 45,946 | 45,781 | 45,545 | 45,396 | 44,923 | 44,448 | 44,307 | 43,886 | 44,345 | 44,479 |
| Linn County | 115,348 | 113,053 | 110,844 | 108,336 | 106,955 | 106,132 | 104,658 | 103,597 | 103,013 | 103,069 |
| Malheur County | 30,907 | 31,013 | 30,878 | 30,968 | 30,994 | 31,133 | 31,322 | 31,474 | 31,520 | 31,615 |
| Marion County | 314,606 | 310,100 | 305,962 | 301,699 | 298,923 | 296,615 | 293,578 | 288,772 | 285,562 | 284,834 |
| Morrow County | 11,140 | 11,120 | 11,311 | 11,288 | 11,382 | 11,404 | 11,390 | 11,090 | 11,019 | 10,995 |
| Multnomah County | 714,567 | 699,186 | 684,693 | 675,175 | 672,660 | 679,187 | 676,775 | 669,766 | 661,766 | 660,486 |
| Polk County | 77,074 | 75,008 | 72,637 | 70,080 | 67,757 | 65,950 | 64,771 | 63,796 | 62,654 | 62,380 |
| Sherman County | 1,638 | 1,664 | 1,641 | 1,659 | 1,668 | 1,747 | 1,757 | 1,845 | 1,921 | 1,934 |
| Tillamook County | 24,927 | 24,958 | 24,962 | 24,832 | 24,666 | 24,486 | 24,350 | 24,332 | 24,253 | 24,262 |
| Umatilla County | 73,526 | 73,237 | 72,994 | 72,918 | 72,772 | 72,295 | 71,820 | 70,501 | 70,698 | 70,548 |
| Union County | 24,961 | 24,737 | 24,436 | 24,449 | 24,337 | 24,473 | 24,467 | 24,347 | 24,546 | 24,530 |
| Wallowa County | 6,760 | 6,746 | 6,742 | 6,820 | 6,856 | 6,972 | 7,019 | 7,098 | 7,215 | 7,226 |
| Wasco County | 23,775 | 23,705 | 23,552 | 23,401 | 23,393 | 23,560 | 23,491 | 23,699 | 23,820 | 23,791 |
| Washington County | 529,216 | 519,794 | 510,927 | 498,151 | 486,036 | 478,630 | 471,724 | 462,481 | 448,509 | 445,342 |
| Wheeler County | 1,319 | 1,357 | 1,373 | 1,396 | 1,457 | 1,503 | 1,523 | 1,496 | 1,543 | 1,547 |
| Yamhill County | 98,168 | 96,299 | 93,474 | 91,176 | 89,691 | 88,793 | 87,533 | 86,280 | 85,247 | 84,992 |
Source: Population Division, U.S. Census Bureau