Photo : NASA Earth Observatory/NOAA NGDC

South Dakota: population and ages

935 000 people lived in South Dakota on 1 July 2025, by the US Census Bureau’s estimate.

Half of them were younger than 38,4 years. For the United States as a whole, the median age was 39,4.

Since 1 July 2020, the population has grown by 5,3 %, or 47 286 people. The United States changed by +3,1 % in the same years.

  • Median age38,4
  • Under 1823,5 %
  • 65 and over19,4 %
  • Rank by population46 of 51
  • Change since 2020+5,3 %
Population pyramid, South Dakota, 1 July 2025HommesFemmes0102030405060708085+05 k5 k10 k10 k15 k15 k
Population pyramid, South Dakota, 1 July 2025

You in South Dakota

Choose South Dakota as your state, next to the United States, in Your life and in the age tools: your age among the people who live there, and the generations they belong to.

Population, 2010 to 2025

Population on 1 July0250 k500 k750 k1 M2010201520202025
2025 South Dakota: 935,1 k

Estimates for 2010 to 2019 are based on the 2010 census, those from 2020 on the 2020 census. The Census Bureau does not join the two series, so part of any step between 2019 and 2020 comes from the new base, not from a change in population.

Ages

In 2025, 23,5 % of the people in South Dakota were under 18 and 19,4 % were 65 or older. For the United States: 21,1 % and 18,9 %.

Median age on 1 July0,010,020,030,040,02010201520202025États-UnisSouth Dakota
2025 South Dakota: 38,4États-Unis: 39,4

Ages are counted up to 85 and over, and the median age is worked out from them.

States of a similar size
  1. Montana1,1 M
  2. Rhode Island1,1 M
  3. Delaware1,1 M
  4. South Dakota935,1 k
  5. North Dakota799,4 k
  6. Alaska737,3 k
  7. District of Columbia693,6 k

Sources: US Census Bureau, Population Division, state population estimates by single year of age and sex (Vintage 2025 and Vintage 2020), public domain.