STATE ยท IA

Counties in Iowa

Iowa has 99 counties and county equivalents. The most populous is Polk County with 505,255 people (Census 2023 estimate).

CountyTypeFIPSPopulation (2023)
Adair Countycounty190017,389
Adams Countycounty190033,544
Allamakee Countycounty1900514,074
Appanoose Countycounty1900712,119
Audubon Countycounty190095,534
Benton Countycounty1901125,796
Black Hawk Countycounty19013130,471
Boone Countycounty1901526,590
Bremer Countycounty1901725,307
Buchanan Countycounty1901920,691
Buena Vista Countycounty1902120,567
Butler Countycounty1902314,172
Calhoun Countycounty190259,763
Carroll Countycounty1902720,522
Cass Countycounty1902913,130
Cedar Countycounty1903118,302
Cerro Gordo Countycounty1903342,406
Cherokee Countycounty1903511,605
Chickasaw Countycounty1903711,658
Clarke Countycounty190399,588
Clay Countycounty1904116,511
Clayton Countycounty1904316,969
Clinton Countycounty1904546,158
Crawford Countycounty1904716,013
Dallas Countycounty19049111,092
Davis Countycounty190519,169
Decatur Countycounty190537,665
Delaware Countycounty1905517,600
Des Moines Countycounty1905738,253
Dickinson Countycounty1905918,056
Dubuque Countycounty1906198,887
Emmet Countycounty190639,229
Fayette Countycounty1906519,210
Floyd Countycounty1906715,326
Franklin Countycounty190699,875
Fremont Countycounty190716,458
Greene Countycounty190738,584
Grundy Countycounty1907512,384
Guthrie Countycounty1907710,722
Hamilton Countycounty1907914,729
Hancock Countycounty1908110,615
Hardin Countycounty1908316,463
Harrison Countycounty1908514,670
Henry Countycounty1908719,547
Howard Countycounty190899,376
Humboldt Countycounty190919,500
Ida Countycounty190936,833
Iowa Countycounty1909516,381
Jackson Countycounty1909719,342
Jasper Countycounty1909937,919
Jefferson Countycounty1910115,440
Johnson Countycounty19103157,528
Jones Countycounty1910520,900
Keokuk Countycounty191079,914
Kossuth Countycounty1910914,396
Lee Countycounty1911132,565
Linn Countycounty19113228,972
Louisa Countycounty1911510,513
Lucas Countycounty191178,747
Lyon Countycounty1911912,324
Madison Countycounty1912116,971
Mahaska Countycounty1912321,874
Marion Countycounty1912533,770
Marshall Countycounty1912740,014
Mills Countycounty1912914,633
Mitchell Countycounty1913110,518
Monona Countycounty191338,493
Monroe Countycounty191357,504
Montgomery Countycounty1913710,139
Muscatine Countycounty1913942,218
O'Brien Countycounty1914114,012
Osceola Countycounty191435,978
Page Countycounty1914515,014
Palo Alto Countycounty191478,810
Plymouth Countycounty1914925,722
Pocahontas Countycounty191516,976
Polk Countycounty19153505,255
Pottawattamie Countycounty1915593,179
Poweshiek Countycounty1915718,453
Ringgold Countycounty191594,642
Sac Countycounty191619,686
Scott Countycounty19163174,270
Shelby Countycounty1916511,806
Sioux Countycounty1916736,246
Story Countycounty1916998,566
Tama Countycounty1917116,833
Taylor Countycounty191735,924
Union Countycounty1917511,906
Van Buren Countycounty191777,266
Wapello Countycounty1917935,166
Warren Countycounty1918155,205
Washington Countycounty1918322,560
Wayne Countycounty191856,557
Webster Countycounty1918736,485
Winnebago Countycounty1918910,571
Winneshiek Countycounty1919119,815
Woodbury Countycounty19193105,951
Worth Countycounty191957,297
Wright Countycounty1919712,656

Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27. Looking for yours? Find your county.