Ranking of Iowa Counties By Total Voting-age Population (18yrs and over) from Census 2020

Updated on August 22, 2023.

According to the data from the US 2020 Census, as at April 2020, among all the counties in Iowa, Polk County had the highest voting-age population (18 years and over) (371.66K), followed by Linn County (176.91K), and Scott County (133.73K).

The chart below shows the top 10 counties with high voting-age population, and the table below shows the ranking of all Iowa counties based on voting-age population.

You can also see the ranking of counties by population for other states as well as for the whole United States.

Ranking of Iowa Counties By Total Voting-age Population from Census 2020
Polk
371.66K
Linn
176.91K
Scott
133.73K
Johnson
122.08K
Black Hawk
102.53K
Story
82.03K
Woodbury
78.38K
Dubuque
76.92K
Dallas
72.05K
Pottawattamie
71.81K
Ranking of Iowa Counties By Total Voting-age Population from Census 2020
Rank
County
Voting-age Population
1 Polk County 371,655
2 Linn County 176,911
3 Scott County 133,731
4 Johnson County 122,084
5 Black Hawk County 102,527
6 Story County 82,031
7 Woodbury County 78,384
8 Dubuque County 76,916
9 Dallas County 72,050
10 Pottawattamie County 71,810
11 Warren County 39,080
12 Clinton County 35,887
13 Cerro Gordo County 34,430
14 Muscatine County 32,767
15 Des Moines County 30,442
16 Marshall County 30,017
17 Jasper County 29,446
18 Webster County 29,204
19 Wapello County 26,940
20 Lee County 26,398
21 Sioux County 25,861
22 Marion County 25,620
23 Boone County 20,533
24 Benton County 19,458
25 Plymouth County 19,215
Items per page:
1 – 25 of 99