Polk County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 492,401, and was estimated to be 516,546 in 2025, which is also the capital city of Iowa. Polk County is included in the Des Moines–West Des Moines, IA Metropolitan Statistical Area.

History

Polk County was formed on January 13, 1846 and organized on March 1, 1846., the legislative body of the Iowa Territory authorized the creation of twelve counties in the Territory, with general descriptions of their boundaries. On January 17 they further enacted a resolution setting the effective date of the county government for Jasper and Polk Counties as March 1, 1846. Polk County's name referred to United States President James K. Polk, who served from 1845 to 1849.

The first courthouse, a two-story structure, was built in Des Moines in 1846. Rapid settlement and commercial growth in the county soon rendered this building insufficient, so construction of a larger building was initiated in 1858. Due to construction delays and the onset of the Civil War, the structure was not completed until 1866. The present courthouse was erected in 1906, and in 1962 it was extensively renovated and enlarged.

Geography

According to the United States Census Bureau, the county has a total area of , of which is land and (3.24%) is water. It is the 41st-largest county in Iowa by total area The county is bisected by the Des Moines River.

Major highways

  • x20px Interstate 35
  • x20px Interstate 80
  • x20px Interstate 235
  • x20px U.S. Highway 6
  • x20px U.S. Highway 65
  • x20px U.S Route 69
  • x20px Iowa Highway 5
  • x20px Iowa Highway 17
  • x20px Iowa Highway 28
  • x20px Iowa Highway 141
  • x20px Iowa Highway 160
  • x20px Iowa Highway 163
  • x20px Iowa Highway 210
  • x20px Iowa Highway 415

Transit

  • Des Moines Area Regional Transit
  • Burlington Trailways
  • Jefferson Lines
  • Des Moines Bus Station

Demographics

As of the second quarter of 2025, the median home value in Polk County was $293,337.

As of the 2024 American Community Survey, there are 211,294 estimated households in Polk County with an average of 2.40 persons per household. The county has a median household income of $82,405. Approximately 9.9% of the county's population lives at or below the poverty line. Polk County has an estimated 69.4% employment rate, with 41.5% of the population holding a bachelor's degree or higher and 92.4% holding a high school diploma. !! Pop. 1990 !! Pop. 2000 !! Pop. 2010 !!

|-

| White alone (NH)

| 280,143<br>(92.40%) || 299,469<br>(91.54%) || 323,785<br>(86.43%) || 347,710<br>(80.74%) || style='background: #ffffe6; |362,260<br>(73.57%)

|-

| Black or African American alone (NH)

| 13,570<br>(4.48%) || 14,618<br>(4.47%) || 17,874<br>(4.77%) || 25,344<br>(5.89%) || style='background: #ffffe6; |34,990<br>(7.11%)

|-

| Native American or Alaska Native alone (NH)

| 712<br>(0.23%) || 834<br>(0.25%) || 878<br>(0.23%) || 894<br>(0.21%) || style='background: #ffffe6; |1,081<br>(0.22%)

|-

| Asian alone (NH)

| 2,204<br>(0.73%) || 5,871<br>(1.79%) || 9,765<br>(2.61%) || 15,118<br>(3.51%) || style='background: #ffffe6; |24,313<br>(4.94%)

|-

| Pacific Islander alone (NH)

| — || — || 178<br>(0.05%) || 228<br>(0.05%) || style='background: #ffffe6; |280<br>(0.06%)

|-

| Other race alone (NH)

| 1,962<br>(0.65%) || 187<br>(0.06%) || 554<br>(0.15%) || 605<br>(0.14%) || style='background: #ffffe6; |1,713<br>(0.35%)

|-

| Mixed race or multiracial (NH)

| — || — || 5,077<br>(1.36%) || 8,094<br>(1.88%) || style='background: #ffffe6; |19,709<br>(4.00%)

|-

| Hispanic or Latino (any race)

| 4,579<br>(1.51%) || 6,161<br>(1.88%) || 16,490<br>(4.40%) || 32,647<br>(7.58%) || style='background: #ffffe6; |48,055<br>(9.76%)

|-

| Total

| 303,170<br>(100.00%) || 327,140<br>(100.00%) || 374,601<br>(100.00%) || 430,640<br>(100.00%) || style='background: #ffffe6; |492,401<br>(100.00%)

|}

2024 estimate

As of the 2024 estimate, there were 516,185 people, 211,294 households, and _ families residing in the county. The population density was . There were 224,898 housing units at an average density of . The racial makeup of the county was 82.8% White (72.7% NH White), 8.2% African American, 0.6% Native American, 5.5% Asian, 0.1% Pacific Islander, _% from some other races and 2.8% from two or more races. Hispanic or Latino people of any race were 11.2% of the population.

2020 census

thumb|right|Population of Polk County from the U.S. census data

As of the 2020 census, there were 492,401 people, 196,891 households, and 121,993 families residing in the county. The population density was . There were 210,184 housing units at an average density of . The racial makeup of the county was 75.93% White, 7.23% African American, 0.46% Native American, 4.98% Asian, 0.06% Pacific Islander, 3.88% from some other races and 7.45% from two or more races. Hispanic or Latino people of any race were 9.76% of the population.

The median age was 36.0 years. 24.5% of residents were under the age of 18 and 14.1% of residents were 65 years of age or older. For every 100 females there were 96.6 males, and for every 100 females age 18 and over there were 94.6 males age 18 and over.

95.5% of residents lived in urban areas, while 4.5% lived in rural areas.

There were 196,891 households in the county, of which 31.1% had children under the age of 18 living in them. Of all households, 45.9% were married-couple households, 19.7% were households with a male householder and no spouse or partner present, and 26.7% were households with a female householder and no spouse or partner present. About 30.1% of all households were made up of individuals and 10.2% had someone living alone who was 65 years of age or older. There were 210,184 housing units, of which 6.3% were vacant. Among occupied housing units, 65.7% were owner-occupied and 34.3% were renter-occupied. The homeowner vacancy rate was 1.5% and the rental vacancy rate was 9.4%.

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Population ranking

The population ranking of the following table is based on the 2020 census of Polk County.

† county seat

{| class="wikitable sortable"

|-

! Rank

! City/Town/etc.

! Municipal type

! Population<br>(2020 Census)

! Population<br>(2024 Estimate)

|- style="background-color:#FFFACD;"

| 1

|Des Moines † (partially in Warren County)

| City

| 214,133

| 213,096

|- style="background-color:#FFFACD;"

| 2

|Ankeny

| City

| 67,887

| 76,727

|- style="background-color:#FFFACD;"

| 3

|West Des Moines (partially in Dallas, Warren and Madison Counties)

| City

| 68,723

| 73,664

|- style="background-color:#FFFACD;"

| 4

|Urbandale (partially in Dallas County)

| City

| 45,580

| 48,119

|- style="background-color:#FFFACD;"

| 5

|Johnston

| City

| 24,064

| 25,292

|- style="background-color:#FFFACD;"

| 6

|Altoona

| City

| 19,565

| 22,598

|- style="background-color:#FFFACD;"

| 7

|Clive (partially in Dallas County)

| City

| 18,601

| 19,808

|- style="background-color:#FFFACD;"

| 8

|Grimes (partially in Dallas County)

| City

| 15,392

| 17,766

|- style="background-color:#FFFACD;"

| 9

|Norwalk (mostly in Warren County)

| City

| 12,799

| 15,396

|- style="background-color:#FFFACD;"

| 10

|Pleasant Hill

| City

| 10,147

| 12,012

|- style="background-color:#FFFACD;"

| 11

|Bondurant

| City

| 7,365

| 9,565

|- style="background-color:#FFFACD;"

| 12

|Polk City

| City

| 5,543

| 6,545

|- style="background-color:#FFFACD;"

| 13

|Windsor Heights

| City

| 5,252

| 5,106

|- style="background-color:#FFFACD;"

| 14

|Carlisle (partially in Warren County)

| City

| 4,160

| 4,512

|- style="background-color:#F0FFF0;"

| 15

|Saylorville

| CDP

| 3,584

| 3,622

|- style="background-color:#FFFACD;"

| 16

|Mitchellville (partially in Jasper County)

| City

| 2,485

| 2,717

|- style="background-color:#FFFACD;"

| 17

|Granger (mostly in Dallas County)

| City

| 1,654

| 2,191

|- style="background-color:#FFFACD;"

| 18

|Elkhart

| City

| 882

| 1,165

|- style="background-color:#FFFACD;"

| 19

|Runnells

| City

| 457

| 467

|- style="background-color:#FFFACD;"

| 20

|Alleman

| City

| 423

| 447

|- style="background-color:#FFFACD;"

| 21

|Sheldahl (partially in Boone and Story Counties)

| City

| 297

| 326

|}

Education

School districts include:

  • Ankeny Community School District, Ankeny
  • Ballard Community School District, Huxley
  • Bondurant–Farrar Community School District, Bondurant
  • Carlisle Community School District, Carlisle
  • Collins–Maxwell Community School District, Maxwell
  • Dallas Center–Grimes Community School District, Grimes
  • Des Moines Independent Community School District, Des Moines
  • Johnston Community School District, Johnston
  • Madrid Community School District, Madrid
  • North Polk Community School District, Alleman
  • PCM Community School District, Monroe
  • Saydel Community School District, Des Moines
  • Southeast Polk Community School District, Pleasant Hill
  • Urbandale Community School District, Urbandale
  • West Des Moines Community School District, West Des Moines
  • Woodward-Granger Community School District, Granger

Attractions

  • Adventureland Resort
  • Blank Park Zoo
  • Casey's Center
  • Iowa State Capitol
  • Iowa State Fair
  • Living History Farms
  • Science Center of Iowa
  • Valley Junction

Communities

Cities

  • Alleman
  • Altoona
  • Ankeny
  • Bondurant
  • Carlisle
  • Clive
  • Des Moines
  • Elkhart
  • Granger
  • Grimes
  • Johnston
  • Mitchellville
  • Norwalk
  • Pleasant Hill
  • Polk City
  • Runnells
  • Sheldahl
  • Urbandale
  • West Des Moines
  • Windsor Heights

Census-designated place

  • Saylorville

Unincorporated communities

  • Adelphi
  • Andrews
  • Avon
  • Avon Lake
  • Berwick
  • Capitol Heights
  • Crocker
  • Enterprise
  • Farrar
  • Herrold
  • Ivy
  • Lovington
  • Norwoodville
  • Oralabor
  • Polk City Junction
  • Rising Sun
  • Santiago
  • Saylor
  • Swanwood
  • White Oak
  • Zook Spur

Townships

  • Allen
  • Beaver
  • Bloomfield
  • Camp
  • Clay
  • Crocker
  • Delaware
  • Des Moines
  • Douglas
  • Elkhart
  • Four Mile
  • Franklin
  • Jefferson
  • Lee
  • Lincoln
  • Madison
  • Saylor
  • Union
  • Walnut
  • Washington
  • Webster

See also

  • Polk County Courthouse
  • Iowa State Capitol
  • Terrace Hill also known as Hubbell Mansion, Benjamin F. Allen House, or the Iowa Governor's Mansion
  • National Register of Historic Places listings in Polk County, Iowa

References

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  • Polk County – government website