Data / Rankings / Population under 18 / Counties in South Dakota

Counties in South Dakota by population under 18

Todd County had the highest population under 18 of 66 counties in 2019, at 40.2%. Custer County had the lowest, at 16.8%. The median was 23.5% and the figure for South Dakota was 24.6%. Source: the U.S. Census Bureau.

Highest40.2Todd County
Lowest16.8Custer County
Median23.566 counties
South Dakota24.6History

Top 40 counties, 2019

Todd County: 40.2 %Todd County40.2Buffalo County: 39.2 %Buffalo County39.2Oglala Lakota County: 37.2 %Oglala Lakota County37.2Corson County: 35.8 %Corson County35.8Ziebach County: 34.9 %Ziebach County34.9Jackson County: 32.7 %Jackson County32.7Bennett County: 32.6 %Bennett County32.6Dewey County: 32.4 %Dewey County32.4Mellette County: 32.2 %Mellette County32.2Hamlin County: 32.1 %Hamlin County32.1Lyman County: 30 %Lyman County30Hanson County: 29.9 %Hanson County29.9Charles Mix County: 28.8 %Charles Mix County28.8Lincoln County: 28.5 %Lincoln County28.5Roberts County: 28.2 %Roberts County28.2Beadle County: 27.1 %Beadle County27.1Clark County: 26.8 %Clark County26.8Moody County: 26.5 %Moody County26.5McCook County: 25.5 %McCook County25.5Turner County: 25.5 %Turner County25.5Meade County: 25.2 %Meade County25.2Aurora County: 25.2 %Aurora County25.2Stanley County: 25.2 %Stanley County25.2Hutchinson County: 25.1 %Hutchinson County25.1Minnehaha County: 25.1 %Minnehaha County25.1Harding County: 24.8 %Harding County24.8Union County: 24.8 %Union County24.8Sanborn County: 24.8 %Sanborn County24.8Butte County: 23.9 %Butte County23.9Hughes County: 23.8 %Hughes County23.8Tripp County: 23.8 %Tripp County23.8Codington County: 23.6 %Codington County23.6Spink County: 23.5 %Spink County23.5Brown County: 23.5 %Brown County23.5Marshall County: 23.5 %Marshall County23.5Brule County: 23.4 %Brule County23.4Haakon County: 23.2 %Haakon County23.2Day County: 23.2 %Day County23.2Jerauld County: 23.2 %Jerauld County23.2Douglas County: 23.2 %Douglas County23.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2019 (%)Change on 2018
1Todd County40.2-0.4 pts
2Buffalo County39.2-0 pts
3Oglala Lakota County37.2-0.6 pts
4Corson County35.8-0.8 pts
5Ziebach County34.9-0.1 pts
6Jackson County32.7+1.3 pts
7Bennett County32.6-0.4 pts
8Dewey County32.4-0.7 pts
9Mellette County32.2-0.3 pts
10Hamlin County32.1+0.8 pts
11Lyman County30+0.1 pts
12Hanson County29.9-0.4 pts
13Charles Mix County28.8-0.2 pts
14Lincoln County28.5-0.2 pts
15Roberts County28.2+0.1 pts
16Beadle County27.1+0.2 pts
17Clark County26.8+0.5 pts
18Moody County26.5+0.6 pts
19McCook County25.5-0.1 pts
20Turner County25.5+0.1 pts
21Meade County25.2-0.1 pts
22Aurora County25.2-0.4 pts
23Stanley County25.2+0.8 pts
24Hutchinson County25.1+0.2 pts
25Minnehaha County25.1-0.1 pts
26Harding County24.8+0.3 pts
27Union County24.8+0.1 pts
28Sanborn County24.8-0.1 pts
29Butte County23.9+0.4 pts
30Hughes County23.8+0.2 pts
31Tripp County23.8+0.5 pts
32Codington County23.6-0.3 pts
33Spink County23.5+0.2 pts
34Brown County23.5-0.3 pts
35Marshall County23.5+0.2 pts
36Brule County23.4-0.2 pts
37Haakon County23.2-0.6 pts
38Day County23.2-0.1 pts
39Jerauld County23.2-0.6 pts
40Douglas County23.2-0.2 pts
41Deuel County23.1-0.2 pts
42Kingsbury County23.1+0.4 pts
43Edmunds County23-0.2 pts
44Walworth County22.9+0.2 pts
45Miner County22.8-0.2 pts
46Davison County22.80 pts
47Grant County22.70 pts
48Pennington County22.7-0.3 pts
49Gregory County22.4-0.3 pts
50Faulk County22.4-0.3 pts
51Jones County22.1-0.7 pts
52Lake County21.8+0.3 pts
53McPherson County21.7-0.2 pts
54Hand County21.4-0.4 pts
55Yankton County21.1-0.1 pts
56Perkins County21+0.1 pts
57Brookings County20.9+0.2 pts
58Sully County20.9+0.3 pts
59Campbell County20.3+1.4 pts
60Hyde County19.5-0.4 pts
61Potter County19.4-0.7 pts
62Lawrence County19-0.1 pts
63Bon Homme County18.7-0.3 pts
64Fall River County17.1-0.1 pts
65Clay County17.1+0.1 pts
66Custer County16.8+0.1 pts

Other periods

About this ranking

Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.

Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in South Dakota by population under 18, 2019) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in South Dakota by population under 18, 2019. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in South Dakota by population under 18, 2019. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in South Dakota by population under 18, 2019 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_south_dakota_2019,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in South Dakota by population under 18, 2019}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in South Dakota by population under 18, 2019
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/south-dakota-counties?period=2019.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -
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Questions

Which county has the highest population under 18?

Todd County, with 40.2% in 2019, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Custer County, with 16.8% in 2019.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.

Population under 18: other rankings

Counties in South Dakota: more rankings