Johnston, IA Demographics

A map of Johnston's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	18,505	19,401	75.9%	80.6%
Black	2,590	1,393	10.6%	5.8%
Asian	1,772	1,506	7.3%	6.3%
Multiracial	825	740	3.4%	3.1%
Hispanic	648	934	2.7%	3.9%
Native American/Other	44	90	0.2%	0.4%

Johnston, Iowa has an estimated population of 24,384, a slight increase from the 24,064 recorded in the 2020 Census. The population is 75.9% White, 10.6% Black, 7.3% Asian, 3.4% Multiracial, 2.7% Hispanic, and 0.2% Native American/Other. This demographic dot map shows the population of Johnston, with one dot drawn for each person counted by the Census, color-coded by race.

Johnston has become considerably more racially diverse since 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 Johnston, that probability was 34.0% in 2020 and 40.6% in the most recent ACS estimates.

Johnston is ranked the 21st most populous place in Iowa, out of 1,026 places. This ranking is based on the Census definition of a place, which includes incorporated places like cities, towns, and villages, as well as unincorporated census-designated places (CDPs). Johnston was ranked the 21st most populous place in the 2020 Census.

Johnston's White Population

18,505 residents of Johnston, or 75.9% of the population, identify as White. The share of White residents in Johnston is lower than in Iowa overall, where 82.3% of the population is White. Johnston ranks 955th statewide in terms of White residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's White population has declined by an estimated 4.6%. White residents' share of Johnston's population has decreased from 80.6% to 75.9%.

Johnston is less White than neighboring Grimes (81.6% White), Urbandale (79.4% White), Windsor Heights (81.4% White), Polk City (96.2% White), and Saylorville (88.1% White).

Johnston's Black Population

2,590 residents of Johnston, or 10.6% of the population, identify as Black. The share of Black residents in Johnston is higher than in Iowa overall, where 3.8% of the population is Black. Johnston ranks 18th statewide in terms of Black residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's Black population has grown by an estimated 85.9%. Black residents' share of Johnston's population has increased from 5.8% to 10.6%.

Johnston is more Black than neighboring Grimes (6.2% Black), Urbandale (4.8% Black), Windsor Heights (5.6% Black), Polk City (0.2% Black), and Saylorville (0% Black).

Johnston's Asian Population

1,772 residents of Johnston, or 7.3% of the population, identify as Asian. The share of Asian residents in Johnston is slightly higher than in Iowa overall, where 2.5% of the population is Asian. Johnston ranks 12th statewide in terms of Asian residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's Asian population has grown by an estimated 17.7%. Asian residents' share of Johnston's population has increased from 6.3% to 7.3%.

Johnston is more Asian than neighboring Grimes (4.6% Asian), Urbandale (4.9% Asian), Windsor Heights (4.7% Asian), Polk City (0% Asian), and Saylorville (1.8% Asian).

Johnston's Hispanic Population

648 residents of Johnston, or 2.7% of the population, identify as Hispanic. The share of Hispanic residents in Johnston is slightly lower than in Iowa overall, where 7.3% of the population is Hispanic. Johnston ranks 303rd statewide in terms of Hispanic residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's Hispanic population has declined by an estimated 30.6%. Hispanic residents' share of Johnston's population has decreased from 3.9% to 2.7%.

Johnston is more Hispanic than neighboring Polk City (2.5% Hispanic). Johnston is less Hispanic than neighboring Grimes (5.3% Hispanic), Urbandale (7.2% Hispanic), Windsor Heights (4.3% Hispanic), and Saylorville (3.8% Hispanic).

Johnston's Native American/Other Population

44 residents of Johnston, or 0.2% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Johnston is comparable to the share in Iowa overall, where 0.6% of the population is Native American/Other. Johnston ranks 437th statewide in terms of Native American/Other residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's Native American/Other population has declined by an estimated 51.1%. Native American/Other residents' share of Johnston's population has remained roughly unchanged at 0.2%.

Johnston is more Native American/Other than neighboring Grimes (0% Native American/Other), Windsor Heights (0% Native American/Other), Polk City (0% Native American/Other), and Saylorville (0% Native American/Other). Johnston is less Native American/Other than neighboring Urbandale (0.4% Native American/Other).

Johnston's Multiracial Population

825 residents of Johnston, or 3.4% of the population, identify as Multiracial. The share of Multiracial residents in Johnston is comparable to the share in Iowa overall, where 3.5% of the population is Multiracial. Johnston ranks 397th statewide in terms of Multiracial residents as a share of the population, out of 1,026 places.

Since the 2020 Census, Johnston's Multiracial population has grown by an estimated 11.5%. Multiracial residents' share of Johnston's population has remained roughly unchanged at 3.4%.

Johnston is more Multiracial than neighboring Grimes (2.3% Multiracial), Urbandale (3.3% Multiracial), and Polk City (1.1% Multiracial). Johnston is less Multiracial than neighboring Windsor Heights (4.1% Multiracial), and Saylorville (6.2% 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.