Iowa 2020 Census Total Voting-age Population (18yrs and over) By County
According to the data from the US 2020 decennial Census, as at April 2020, the total Voting-age population (18 years and over) of Iowa was 2,450,103, which was 76.80% of the total Iowa population.
Polk County had the highest voting-age population (371,655), followed by Linn County (176,911), and then Scott County (133,731). On the other hand, the 3 counties with low voting-age population were: Adams County (2,891), Ringgold County (3,623), and Audubon County (4,437).
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 voting-age population by county for the different racial groups as well as the different ethnicities in Iowa.
| County | Voting-age Population | % of Iowa Pop. |
|---|---|---|
| Adair | 5834 | 0.24 |
| Adams | 2891 | 0.12 |
| Allamakee | 10782 | 0.44 |
| Appanoose | 9608 | 0.39 |
| Audubon | 4437 | 0.18 |
| Benton | 19458 | 0.79 |
| Black Hawk | 102527 | 4.18 |
| Boone | 20533 | 0.84 |
| Bremer | 19135 | 0.78 |
| Buchanan | 15150 | 0.62 |
| Buena Vista | 15327 | 0.63 |
| Butler | 11127 | 0.45 |
| Calhoun | 7806 | 0.32 |
| Carroll | 15779 | 0.64 |
| Cass | 10235 | 0.42 |
| Cedar | 14283 | 0.58 |
| Cerro Gordo | 34430 | 1.41 |
| Cherokee | 9132 | 0.37 |
| Chickasaw | 9183 | 0.38 |
| Clarke | 7332 | 0.30 |
| Clay | 12704 | 0.52 |
| Clayton | 13339 | 0.54 |
| Clinton | 35887 | 1.47 |
| Crawford | 12099 | 0.49 |
| Dallas | 72050 | 2.94 |
| Davis | 6384 | 0.26 |
| Decatur | 5873 | 0.24 |
| Delaware | 13359 | 0.55 |
| Des Moines | 30442 | 1.24 |
| Dickinson | 14332 | 0.59 |
| Dubuque | 76916 | 3.14 |
| Emmet | 7330 | 0.30 |
| Fayette | 15310 | 0.63 |
| Floyd | 11969 | 0.49 |
| Franklin | 7668 | 0.31 |
| Fremont | 5121 | 0.21 |
| Greene | 6818 | 0.28 |
| Grundy | 9393 | 0.38 |
| Guthrie | 8232 | 0.34 |
| Hamilton | 11564 | 0.47 |
| Hancock | 8405 | 0.34 |
| Hardin | 13066 | 0.53 |
| Harrison | 11168 | 0.46 |
| Henry | 16167 | 0.66 |
| Howard | 7093 | 0.29 |
| Humboldt | 7266 | 0.30 |
| Ida | 5399 | 0.22 |
| Iowa | 12763 | 0.52 |
| Jackson | 15254 | 0.62 |
| Jasper | 29446 | 1.20 |
| Jefferson | 12724 | 0.52 |
| Johnson | 122084 | 4.98 |
| Jones | 16239 | 0.66 |
| Keokuk | 7654 | 0.31 |
| Kossuth | 11653 | 0.48 |
| Lee | 26398 | 1.08 |
| Linn | 176911 | 7.22 |
| Louisa | 8372 | 0.34 |
| Lucas | 6614 | 0.27 |
| Lyon | 8487 | 0.35 |
| Madison | 12321 | 0.50 |
| Mahaska | 16933 | 0.69 |
| Marion | 25620 | 1.05 |
| Marshall | 30017 | 1.23 |
| Mills | 10925 | 0.45 |
| Mitchell | 8085 | 0.33 |
| Monona | 6822 | 0.28 |
| Monroe | 5796 | 0.24 |
| Montgomery | 8062 | 0.33 |
| Muscatine | 32767 | 1.34 |
| O'Brien | 10884 | 0.44 |
| Osceola | 4782 | 0.20 |
| Page | 12021 | 0.49 |
| Palo Alto | 6971 | 0.28 |
| Plymouth | 19215 | 0.78 |
| Pocahontas | 5473 | 0.22 |
| Polk | 371655 | 15.17 |
| Pottawattamie | 71810 | 2.93 |
| Poweshiek | 15037 | 0.61 |
| Ringgold | 3623 | 0.15 |
| Sac | 7614 | 0.31 |
| Scott | 133731 | 5.46 |
| Shelby | 9108 | 0.37 |
| Sioux | 25861 | 1.06 |
| Story | 82031 | 3.35 |
| Tama | 12990 | 0.53 |
| Taylor | 4516 | 0.18 |
| Union | 9361 | 0.38 |
| Van Buren | 5485 | 0.22 |
| Wapello | 26940 | 1.10 |
| Warren | 39080 | 1.60 |
| Washington | 17073 | 0.70 |
| Wayne | 4792 | 0.20 |
| Webster | 29204 | 1.19 |
| Winnebago | 8473 | 0.35 |
| Winneshiek | 16206 | 0.66 |
| Woodbury | 78384 | 3.20 |
| Worth | 5760 | 0.24 |
| Wright | 9733 | 0.40 |