USStateMap

Iowa County Map

Iowa has 99 counties. Polk County is the most populous, with 492,401 residents in 2020, and Kossuth County is the largest by land area at 972.7 sq mi. The capital, Des Moines, is the seat of Polk County.

County map of Iowa showing all 99 counties

County lines are switched on when the interactive map loads, over an OpenStreetMap base map with major cities (capital in red). Hover over a county to see its name, or untick Show counties to hide the lines.

99counties
Polkmost populous: 492,401
Kossuthlargest: 972.7 sq mi of land
Dickinsonsmallest: 380.5 sq mi of land

List of Iowa counties

CountyCounty seatPopulation (2020)Land area (sq mi)
Adair CountyGreenfield7,496569.3
Adams CountyCorning3,704423.4
Allamakee CountyWaukon14,061639.0
Appanoose CountyCenterville12,317497.3
Audubon CountyAudubon5,674443.0
Benton CountyVinton25,575716.1
Black Hawk CountyWaterloo131,144565.8
Boone CountyBoone26,715570.5
Bremer CountyWaverly24,988435.5
Buchanan CountyIndependence20,565571.1
Buena Vista CountyStorm Lake20,823574.9
Butler CountyAllison14,334580.1
Calhoun CountyRockwell City9,927569.8
Carroll CountyCarroll20,760569.5
Cass CountyAtlantic13,127564.3
Cedar CountyTipton18,505579.5
Cerro Gordo CountyMason City43,127568.3
Cherokee CountyCherokee11,658576.9
Chickasaw CountyNew Hampton12,012504.3
Clarke CountyOsceola9,748431.1
Clay CountySpencer16,384567.2
Clayton CountyElkader17,043778.5
Clinton CountyClinton46,460695.0
Crawford CountyDenison16,525714.2
Dallas CountyAdel99,678588.3
Davis CountyBloomfield9,110502.2
Decatur CountyLeon7,645531.9
Delaware CountyManchester17,488577.7
Des Moines CountyBurlington38,910416.1
Dickinson CountySpirit Lake17,703380.5
Dubuque CountyDubuque99,266608.3
Emmet CountyEstherville9,388395.9
Fayette CountyWest Union19,509730.8
Floyd CountyCharles City15,627500.6
Franklin CountyHampton10,019582.0
Fremont CountySidney6,605511.2
Greene CountyJefferson8,771569.6
Grundy CountyGrundy Center12,329501.9
Guthrie CountyGuthrie Center10,623590.6
Hamilton CountyWebster City15,039576.7
Hancock CountyGarner10,795571.0
Hardin CountyEldora16,878569.3
Harrison CountyLogan14,582696.9
Henry CountyMount Pleasant20,482434.3
Howard CountyCresco9,469473.2
Humboldt CountyDakota City9,597434.4
Ida CountyIda Grove7,005431.5
Iowa CountyMarengo16,662586.5
Jackson CountyMaquoketa19,485636.0
Jasper CountyNewton37,813730.4
Jefferson CountyFairfield15,663435.5
Johnson CountyIowa City152,854613.0
Jones CountyAnamosa20,646575.6
Keokuk CountySigourney10,033579.2
Kossuth CountyAlgona14,828972.7
Lee CountyFort Madison and Keokuk33,555517.6
Linn CountyCedar Rapids230,299717.1
Louisa CountyWapello10,837401.8
Lucas CountyChariton8,634430.7
Lyon CountyRock Rapids11,934587.6
Madison CountyWinterset16,548561.0
Mahaska CountyOskaloosa22,190570.9
Marion CountyKnoxville33,414554.5
Marshall CountyMarshalltown40,105572.5
Mills CountyGlenwood14,484437.4
Mitchell CountyOsage10,565469.3
Monona CountyOnawa8,751694.1
Monroe CountyAlbia7,577433.7
Montgomery CountyRed Oak10,330424.1
Muscatine CountyMuscatine43,235437.4
O'Brien CountyPrimghar14,182573.0
Osceola CountySibley6,192398.7
Page CountyClarinda15,211534.9
Palo Alto CountyEmmetsburg8,996563.9
Plymouth CountyLe Mars25,698862.8
Pocahontas CountyPocahontas7,078577.2
Polk CountyDes Moines492,401572.2
Pottawattamie CountyCouncil Bluffs93,667951.3
Poweshiek CountyMontezuma18,662584.9
Ringgold CountyMount Ayr4,663535.5
Sac CountySac City9,814575.0
Scott CountyDavenport174,669458.1
Shelby CountyHarlan11,746590.8
Sioux CountyOrange City35,872767.9
Story CountyNevada98,537572.5
Tama CountyToledo17,135721.0
Taylor CountyBedford5,896531.9
Union CountyCreston12,138423.6
Van Buren CountyKeosauqua7,203484.8
Wapello CountyOttumwa35,437431.8
Warren CountyIndianola52,403569.8
Washington CountyWashington22,565568.8
Wayne CountyCorydon6,497525.5
Webster CountyFort Dodge36,999715.7
Winnebago CountyForest City10,679400.5
Winneshiek CountyDecorah20,070689.8
Woodbury CountySioux City105,941872.9
Worth CountyNorthwood7,443400.1
Wright CountyClarion12,943580.4

Click a column heading to sort. Land area excludes water. Lee County has two county seats.

Most populous counties

Iowa had 3,190,369 residents in the 2020 Census. The five most populous counties held 37.0 percent of them:

  1. Polk County (seat Des Moines): 492,401, or 15.4 percent of the state
  2. Linn County (seat Cedar Rapids): 230,299, or 7.2 percent of the state
  3. Scott County (seat Davenport): 174,669, or 5.5 percent of the state
  4. Johnson County (seat Iowa City): 152,854, or 4.8 percent of the state
  5. Black Hawk County (seat Waterloo): 131,144, or 4.1 percent of the state

The least populous is Adams County, with 3,704 residents. The median Iowa county had 15,211 people in 2020.

Largest and smallest counties

By land area, the largest Iowa counties are Kossuth County (972.7 sq mi), Pottawattamie County (951.3 sq mi) and Woodbury County (872.9 sq mi). The smallest are Dickinson County (380.5 sq mi), Emmet County (395.9 sq mi) and Osceola County (398.7 sq mi).

The average Iowa county covers 564.2 sq mi of land. Kossuth County is 2.6 times the land area of Dickinson County.

How counties work in Iowa

Most of Iowa’s 99 counties are near-square blocks laid out on the federal public land survey grid, which gives the county map its checkerboard pattern. Each county is governed by an elected board of supervisors.

Lee County, in the far southeast corner on the Mississippi River, is the only Iowa county with two county seats: Fort Madison and Keokuk, each with its own courthouse.

Polk County holds Des Moines, the capital and largest city, along with suburbs such as Ankeny.

Printable Iowa county maps

Download the labeled map with every county name, or the blank county map for quizzes and coloring; both are SVG files that print sharply at any size and are free for personal and classroom use.

Labeled county map of Iowa
Labeled SVGBlank SVGState outline PNG

Frequently asked questions

How many counties are in Iowa?

Iowa has 99 counties. Polk County has the most people and Adams County the fewest.

What is the largest county in Iowa?

Kossuth County, with 972.7 sq mi of land. Its seat is Algona.

What is the most populous county in Iowa?

Polk County, with 492,401 residents in the 2020 Census, 15.4 percent of the state total.

Which Iowa county has two county seats?

Lee County, with courthouses in Fort Madison and Keokuk.

More Iowa and county maps

See the Iowa state map for cities, geography and highways.

County maps of neighboring states: Illinois · Minnesota · Missouri · Nebraska · South Dakota · Wisconsin

Browse all 50 state maps.

Sources: U.S. Census Bureau (2020 Census, 2020 Gazetteer, boundaries); county seats from Wikipedia county lists cross-checked with Wikidata. Last reviewed October 2026.