Polk County Demographics

A map of Polk County's Population by Race

Polk County, Iowa has an estimated population of 503,175, a slight increase from the 492,401 recorded in the 2020 Census. The population is 73.2% White, 10.4% Hispanic, 7.3% Black, 4.9% Asian, 3.8% Multiracial, and 0.4% Native American/Other. This demographic dot map shows the population of Polk County, with one dot drawn for each person counted by the Census, color-coded by race.

Polk is about as racially diverse as it was in the 2020 Census. It is considerably more diverse than Iowa overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Polk County, that probability was 44.0% in 2020 and 44.5% in the most recent ACS estimates.

Polk County is ranked the most populous county in Iowa, out of 99 counties. Polk County was ranked the 1st most populous county in the 2020 Census.

Polk County's White Population

368,110 residents of Polk County, or 73.2% of the population, identify as White. The share of White residents in Polk County is lower than in Iowa overall, where 82.3% of the population is White. Polk County ranks 95th statewide in terms of White residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's White population has grown by an estimated 1.6%. White residents' share of Polk County's population has remained roughly unchanged at 73.2%.

Polk County is less White than neighboring Warren County (91.9% White), Story County (81% White), Dallas County (80.9% White), Boone County (92.9% White), and Jasper County (90.8% White).

Polk County's Black Population

36,704 residents of Polk County, or 7.3% of the population, identify as Black. The share of Black residents in Polk County is slightly higher than in Iowa overall, where 3.8% of the population is Black. Polk County ranks 4th statewide in terms of Black residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's Black population has grown by an estimated 4.9%. Black residents' share of Polk County's population has remained roughly unchanged at 7.3%.

Polk County is more Black than neighboring Warren County (0.7% Black), Story County (2.7% Black), Dallas County (3% Black), Boone County (1.2% Black), and Jasper County (1.5% Black).

Polk County's Asian Population

24,778 residents of Polk County, or 4.9% of the population, identify as Asian. The share of Asian residents in Polk County is slightly higher than in Iowa overall, where 2.5% of the population is Asian. Polk County ranks 5th statewide in terms of Asian residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's Asian population has grown by an estimated 1.9%. Asian residents' share of Polk County's population has remained roughly unchanged at 4.9%.

Polk County is more Asian than neighboring Warren County (0.7% Asian), Boone County (0.2% Asian), and Jasper County (0.7% Asian). Polk County is less Asian than neighboring Story County (6.6% Asian).

Polk County's Hispanic Population

52,317 residents of Polk County, or 10.4% of the population, identify as Hispanic. The share of Hispanic residents in Polk County is slightly higher than in Iowa overall, where 7.3% of the population is Hispanic. Polk County ranks 13th statewide in terms of Hispanic residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's Hispanic population has grown by an estimated 8.9%. Hispanic residents' share of Polk County's population has increased from 9.8% to 10.4%.

Polk County is more Hispanic than neighboring Warren County (3.7% Hispanic), Story County (5.2% Hispanic), Dallas County (6.9% Hispanic), Boone County (2.9% Hispanic), and Jasper County (3.1% Hispanic).

Polk County's Native American/Other Population

1,968 residents of Polk County, or 0.4% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Polk County is comparable to the share in Iowa overall, where 0.6% of the population is Native American/Other. Polk County ranks 23rd statewide in terms of Native American/Other residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's Native American/Other population has declined by an estimated 36.0%. Native American/Other residents' share of Polk County's population has remained roughly unchanged at 0.4%.

Polk County is more Native American/Other than neighboring Warren County (0.2% Native American/Other), Boone County (0% Native American/Other), and Jasper County (0.3% Native American/Other). Polk County is less Native American/Other than neighboring Story County (0.5% Native American/Other), and Dallas County (0.5% Native American/Other).

Polk County's Multiracial Population

19,298 residents of Polk County, or 3.8% of the population, identify as Multiracial. The share of Multiracial residents in Polk County is comparable to the share in Iowa overall, where 3.5% of the population is Multiracial. Polk County ranks 7th statewide in terms of Multiracial residents as a share of the population, out of 99 counties.

Since the 2020 Census, Polk County's Multiracial population has declined by an estimated 2.1%. Multiracial residents' share of Polk County's population has remained roughly unchanged at 3.8%.

Polk County is more Multiracial than neighboring Warren County (2.8% Multiracial), Boone County (2.8% Multiracial), and Jasper County (3.6% Multiracial). Polk County is less Multiracial than neighboring Story County (4% Multiracial), and Dallas County (3.9% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.