Iowa 2020 Census Total Population By County
The total population of Iowa from the 2020 Census was 3,190,369, based on data from the US Census Bureau.
Polk County was the most populated county (492,401), followed by Linn County (230,299), and then Scott County (174,669). On the other hand, the 3 counties that were least populated include: Adams County (3,704), Ringgold County (4,663), and Audubon County (5,674).
You can also see this information for other states and also for the US by state.
Hover over or click on the counties to see the number and percentage of Iowa population that lives in each county. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.
You can also see the population by county for the different racial groups as well as the different ethnicities in Iowa.
| County | Population | % of Iowa Pop. |
|---|---|---|
| Adair | 7496 | 0.24 |
| Adams | 3704 | 0.12 |
| Allamakee | 14061 | 0.44 |
| Appanoose | 12317 | 0.39 |
| Audubon | 5674 | 0.18 |
| Benton | 25575 | 0.80 |
| Black Hawk | 131144 | 4.11 |
| Boone | 26715 | 0.84 |
| Bremer | 24988 | 0.78 |
| Buchanan | 20565 | 0.65 |
| Buena Vista | 20823 | 0.65 |
| Butler | 14334 | 0.45 |
| Calhoun | 9927 | 0.31 |
| Carroll | 20760 | 0.65 |
| Cass | 13127 | 0.41 |
| Cedar | 18505 | 0.58 |
| Cerro Gordo | 43127 | 1.35 |
| Cherokee | 11658 | 0.37 |
| Chickasaw | 12012 | 0.38 |
| Clarke | 9748 | 0.31 |
| Clay | 16384 | 0.51 |
| Clayton | 17043 | 0.53 |
| Clinton | 46460 | 1.46 |
| Crawford | 16525 | 0.52 |
| Dallas | 99678 | 3.12 |
| Davis | 9110 | 0.29 |
| Decatur | 7645 | 0.24 |
| Delaware | 17488 | 0.55 |
| Des Moines | 38910 | 1.22 |
| Dickinson | 17703 | 0.56 |
| Dubuque | 99266 | 3.11 |
| Emmet | 9388 | 0.29 |
| Fayette | 19509 | 0.61 |
| Floyd | 15627 | 0.49 |
| Franklin | 10019 | 0.31 |
| Fremont | 6605 | 0.21 |
| Greene | 8771 | 0.28 |
| Grundy | 12329 | 0.39 |
| Guthrie | 10623 | 0.33 |
| Hamilton | 15039 | 0.47 |
| Hancock | 10795 | 0.34 |
| Hardin | 16878 | 0.53 |
| Harrison | 14582 | 0.46 |
| Henry | 20482 | 0.64 |
| Howard | 9469 | 0.30 |
| Humboldt | 9597 | 0.30 |
| Ida | 7005 | 0.22 |
| Iowa | 16662 | 0.52 |
| Jackson | 19485 | 0.61 |
| Jasper | 37813 | 1.19 |
| Jefferson | 15663 | 0.49 |
| Johnson | 152854 | 4.79 |
| Jones | 20646 | 0.65 |
| Keokuk | 10033 | 0.31 |
| Kossuth | 14828 | 0.47 |
| Lee | 33555 | 1.05 |
| Linn | 230299 | 7.22 |
| Louisa | 10837 | 0.34 |
| Lucas | 8634 | 0.27 |
| Lyon | 11934 | 0.37 |
| Madison | 16548 | 0.52 |
| Mahaska | 22190 | 0.70 |
| Marion | 33414 | 1.05 |
| Marshall | 40105 | 1.26 |
| Mills | 14484 | 0.45 |
| Mitchell | 10565 | 0.33 |
| Monona | 8751 | 0.27 |
| Monroe | 7577 | 0.24 |
| Montgomery | 10330 | 0.32 |
| Muscatine | 43235 | 1.36 |
| O'Brien | 14182 | 0.45 |
| Osceola | 6192 | 0.19 |
| Page | 15211 | 0.48 |
| Palo Alto | 8996 | 0.28 |
| Plymouth | 25698 | 0.81 |
| Pocahontas | 7078 | 0.22 |
| Polk | 492401 | 15.43 |
| Pottawattamie | 93667 | 2.94 |
| Poweshiek | 18662 | 0.59 |
| Ringgold | 4663 | 0.15 |
| Sac | 9814 | 0.31 |
| Scott | 174669 | 5.48 |
| Shelby | 11746 | 0.37 |
| Sioux | 35872 | 1.12 |
| Story | 98537 | 3.09 |
| Tama | 17135 | 0.54 |
| Taylor | 5896 | 0.19 |
| Union | 12138 | 0.38 |
| Van Buren | 7203 | 0.23 |
| Wapello | 35437 | 1.11 |
| Warren | 52403 | 1.64 |
| Washington | 22565 | 0.71 |
| Wayne | 6497 | 0.20 |
| Webster | 36999 | 1.16 |
| Winnebago | 10679 | 0.34 |
| Winneshiek | 20070 | 0.63 |
| Woodbury | 105941 | 3.32 |
| Worth | 7443 | 0.23 |
| Wright | 12943 | 0.41 |