Iowa Counties by Population (2024)

Population

50K

100K

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200K

250K

300K

350K

400K

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500K

Hover/click a county for data.

99 counties

County
2024 Pop.
Change (2020)
Area (mi²)
Density (/mi²)
Location
Polk County509,3263.31%221890Polk County location
Linn County229,004-0.61%277319Linn County location
Scott County174,7890.1%177382Scott County location
Johnson County158,1413.32%237258Johnson County location
Black Hawk County130,890-0.12%218231Black Hawk County location
Dallas County114,03813.43%227194Dallas County location
Woodbury County106,3440.41%337122Woodbury County location
Dubuque County99,059-0.25%235163Dubuque County location
Story County98,8750.23%221173Story County location
Pottawattamie County93,293-0.4%36798Pottawattamie County location
Warren County56,1076.69%22098Warren County location
Clinton County46,061-0.79%26866Clinton County location
Cerro Gordo County42,386-1.48%21975Cerro Gordo County location
Muscatine County42,041-2.55%16996Muscatine County location
Marshall County40,2070.28%22170Marshall County location
Des Moines County38,264-1.44%16192Des Moines County location
Jasper County37,8890.21%28252Jasper County location
Sioux County36,3651.34%29647Sioux County location
Webster County36,318-1.83%27651Webster County location
Wapello County35,251-0.21%16782Wapello County location
Marion County33,9101.48%21461Marion County location
Lee County32,301-3.67%20062Lee County location
Boone County26,601-0.36%22047Boone County location
Benton County25,8501.18%27636Benton County location
Plymouth County25,7220.12%33330Plymouth County location
Bremer County25,3601.4%16858Bremer County location
Washington County22,5780.16%22040Washington County location
Mahaska County21,777-1.73%22038Mahaska County location
Jones County20,8510.96%22236Jones County location
Buchanan County20,6930.43%22036Buchanan County location
Carroll County20,503-1.08%22036Carroll County location
Buena Vista County20,490-1.52%22236Buena Vista County location
Winneshiek County19,728-1.58%26629Winneshiek County location
Jackson County19,338-0.6%24530Jackson County location
Fayette County19,154-1.5%28226Fayette County location
Henry County18,841-7.85%16843Henry County location
Poweshiek County18,388-1.3%22631Poweshiek County location
Cedar County18,251-1.32%22332Cedar County location
Dickinson County18,0641.67%14747Dickinson County location
Delaware County17,5930.77%22330Delaware County location
Madison County16,9021.64%21730Madison County location
Clayton County16,881-0.89%30022Clayton County location
Tama County16,723-2.1%27823Tama County location
Clay County16,5151.1%21929Clay County location
Hardin County16,312-3.07%22029Hardin County location
Iowa County16,265-2.36%22628Iowa County location
Crawford County15,897-3.56%27622Crawford County location
Floyd County15,304-1.92%19331Floyd County location
Jefferson County15,212-3.07%16835Jefferson County location
Page County14,852-2.23%20728Page County location
Mills County14,7312.31%16934Mills County location
Harrison County14,6600.62%26921Harrison County location
Hamilton County14,655-2.35%22325Hamilton County location
Kossuth County14,327-3.19%37615Kossuth County location
Allamakee County14,1300.42%24722Allamakee County location
Butler County14,098-1.64%22424Butler County location
O'Brien County13,939-1.49%22124O'Brien County location
Cass County13,1230%21823Cass County location
Wright County12,617-2.31%22422Wright County location
Lyon County12,4714.53%22721Lyon County location
Grundy County12,4130.65%19425Grundy County location
Appanoose County12,097-1.55%19224Appanoose County location
Union County11,909-1.84%16428Union County location
Shelby County11,9011.41%22820Shelby County location
Cherokee County11,7200.55%22320Cherokee County location
Chickasaw County11,588-3.34%19523Chickasaw County location
Guthrie County10,7631.42%22818Guthrie County location
Hancock County10,579-1.63%22019Hancock County location
Winnebago County10,503-1.49%15426Winnebago County location
Mitchell County10,492-0.99%18122Mitchell County location
Louisa County10,409-3.75%15526Louisa County location
Montgomery County10,068-2.56%16424Montgomery County location
Keokuk County9,945-0.59%22317Keokuk County location
Franklin County9,804-1.98%22517Franklin County location
Calhoun County9,801-1%22017Calhoun County location
Sac County9,683-1.18%22217Sac County location
Clarke County9,533-2.1%16622Clarke County location
Humboldt County9,479-1.25%16822Humboldt County location
Emmet County9,244-1.1%15323Emmet County location
Howard County9,243-2.59%18320Howard County location
Davis County9,1910.88%19418Davis County location
Palo Alto County8,830-1.74%21816Palo Alto County location
Lucas County8,7922.02%16620Lucas County location
Monona County8,480-3%26812Monona County location
Greene County8,458-3.36%22015Greene County location
Decatur County7,6350.38%20514Decatur County location
Monroe County7,478-1.51%16817Monroe County location
Adair County7,321-2.3%22013Adair County location
Worth County7,283-2.06%15418Worth County location
Van Buren County7,2800.8%18715Van Buren County location
Pocahontas County6,879-2.63%22312Pocahontas County location
Ida County6,761-3.72%16716Ida County location
Wayne County6,6241.72%20313Wayne County location
Fremont County6,441-1.9%19713Fremont County location
Taylor County5,9731.89%20511Taylor County location
Osceola County5,884-5.07%15415Osceola County location
Audubon County5,493-3.34%17112Audubon County location
Ringgold County4,596-0.93%2079Ringgold County location
Adams County3,487-5.99%1638Adams County location
  1. Iowa Profile
  2. Iowa State Data Center
  3. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  4. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  5. American Community Survey (2009 - 2013)
  6. Census QuickFacts
  7. Historical Populations of States and Counties (1790 - 1990)

Sources