Census ACS 2023 · 99 counties
Largest Counties in Iowa
Iowa has 99 counties with Census data available. The largest is Polk County with a population of 497,441. County-level data is important because counties are the primary unit of local government in most states, responsible for courts, elections, public health, and infrastructure. Population distribution across counties reveals where growth is concentrated and where rural decline may be occurring.
Source: Census ACS 2023 5-Year Estimates
| # | County | Population | Median Income |
|---|---|---|---|
| 1 | Wright County | 12,817 | $64,033 |
| 2 | Worth County | 7,380 | $76,875 |
| 3 | Woodbury County | 105,760 | $70,147 |
| 4 | Winneshiek County | 19,972 | $75,652 |
| 5 | Winnebago County | 10,648 | $63,719 |
| 6 | Webster County | 36,848 | $68,054 |
| 7 | Wayne County | 6,518 | $59,118 |
| 8 | Washington County | 22,539 | $71,339 |
| 9 | Warren County | 53,484 | $92,990 |
| 10 | Wapello County | 35,265 | $60,034 |
| 11 | Van Buren County | 7,236 | $60,183 |
| 12 | Union County | 12,038 | $56,813 |
| 13 | Taylor County | 5,901 | $67,279 |
| 14 | Tama County | 16,982 | $67,955 |
| 15 | Story County | 98,592 | $69,006 |
| 16 | Sioux County | 35,984 | $84,736 |
| 17 | Shelby County | 11,757 | $67,690 |
| 18 | Scott County | 174,302 | $76,363 |
| 19 | Sac County | 9,759 | $70,991 |
| 20 | Ringgold County | 4,664 | $69,821 |
| 21 | Poweshiek County | 18,582 | $64,837 |
| 22 | Pottawattamie County | 93,407 | $71,446 |
| 23 | Polk County | 497,441 | $81,621 |
| 24 | Pocahontas County | 7,040 | $63,423 |
| 25 | Plymouth County | 25,699 | $81,600 |
| 26 | Palo Alto County | 8,902 | $68,963 |
| 27 | Page County | 15,168 | $57,752 |
| 28 | Osceola County | 6,114 | $69,138 |
| 29 | O'Brien County | 14,103 | $68,216 |
| 30 | Muscatine County | 42,735 | $69,512 |
| 31 | Montgomery County | 10,254 | $63,190 |
| 32 | Monroe County | 7,546 | $72,518 |
| 33 | Monona County | 8,619 | $62,944 |
| 34 | Mitchell County | 10,548 | $68,704 |
| 35 | Mills County | 14,563 | $87,810 |
| 36 | Marshall County | 39,971 | $72,785 |
| 37 | Marion County | 33,551 | $78,059 |
| 38 | Mahaska County | 22,045 | $69,019 |
| 39 | Madison County | 16,760 | $89,542 |
| 40 | Lyon County | 12,087 | $72,881 |
| 41 | Lucas County | 8,685 | $67,921 |
| 42 | Louisa County | 10,710 | $80,223 |
| 43 | Linn County | 229,463 | $76,421 |
| 44 | Lee County | 33,175 | $59,803 |
| 45 | Kossuth County | 14,610 | $65,656 |
| 46 | Keokuk County | 9,964 | $60,856 |
| 47 | Jones County | 20,799 | $73,071 |
| 48 | Johnson County | 154,881 | $74,721 |
| 49 | Jefferson County | 15,676 | $56,824 |
| 50 | Jasper County | 37,864 | $70,128 |
| 51 | Jackson County | 19,429 | $71,605 |
| 52 | Iowa County | 16,547 | $72,185 |
| 53 | Ida County | 6,944 | $62,841 |
| 54 | Humboldt County | 9,573 | $66,994 |
| 55 | Howard County | 9,459 | $67,336 |
| 56 | Henry County | 20,228 | $64,604 |
| 57 | Harrison County | 14,645 | $77,027 |
| 58 | Hardin County | 16,729 | $64,906 |
| 59 | Hancock County | 10,718 | $70,212 |
| 60 | Hamilton County | 14,893 | $71,750 |
| 61 | Guthrie County | 10,646 | $79,981 |
| 62 | Grundy County | 12,352 | $83,617 |
| 63 | Greene County | 8,722 | $59,159 |
| 64 | Fremont County | 6,570 | $73,750 |
| 65 | Franklin County | 9,977 | $63,648 |
| 66 | Floyd County | 15,502 | $64,500 |
| 67 | Fayette County | 19,393 | $58,764 |
| 68 | Emmet County | 9,316 | $65,181 |
| 69 | Dubuque County | 98,948 | $75,919 |
| 70 | Dickinson County | 17,844 | $74,570 |
| 71 | Des Moines County | 38,597 | $60,662 |
| 72 | Delaware County | 17,549 | $76,205 |
| 73 | Decatur County | 7,669 | $57,146 |
| 74 | Davis County | 9,127 | $79,505 |
| 75 | Dallas County | 104,136 | $102,349 |
| 76 | Crawford County | 16,289 | $65,039 |
| 77 | Clinton County | 46,383 | $65,177 |
| 78 | Clayton County | 17,069 | $62,326 |
| 79 | Clay County | 16,446 | $64,082 |
| 80 | Clarke County | 9,690 | $66,821 |
| 81 | Chickasaw County | 11,868 | $73,421 |
| 82 | Cherokee County | 11,587 | $64,478 |
| 83 | Cerro Gordo County | 42,785 | $65,537 |
| 84 | Cedar County | 18,427 | $79,080 |
| 85 | Cass County | 13,115 | $61,657 |
| 86 | Carroll County | 20,677 | $68,528 |
| 87 | Calhoun County | 9,858 | $66,875 |
| 88 | Butler County | 14,301 | $69,651 |
| 89 | Buena Vista County | 20,684 | $66,564 |
| 90 | Buchanan County | 20,645 | $78,430 |
| 91 | Bremer County | 25,118 | $83,343 |
| 92 | Boone County | 26,669 | $79,741 |
| 93 | Black Hawk County | 130,693 | $64,581 |
| 94 | Benton County | 25,698 | $84,742 |
| 95 | Audubon County | 5,622 | $54,152 |
| 96 | Appanoose County | 12,242 | $51,146 |
| 97 | Allamakee County | 14,038 | $66,000 |
| 98 | Adams County | 3,641 | $68,828 |
| 99 | Adair County | 7,471 | $66,176 |
More Rankings for Iowa
Frequently Asked Questions
Polk County is the #1 ranked county in Iowa by population, with a value of 497,441 according to Census ACS 2023 data.
Iowa has 99 counties tracked in Census ACS 2023 data.
All data comes from the American Community Survey (ACS) 2023 5-Year estimates by the US Census Bureau.
Data from the American Community Survey 2023 5-Year estimates. Covers all counties in Iowa.