How many people live in Pennington County, SD?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 116,000 people living in Pennington County, SD. That makes Pennington County the second-most populous county in South Dakota. It is home to 12.4% of people living in the state.
116K
population of Pennington County, SD (2024)
12.4%
County share of the South Dakota population (2024)
About 116,000 people lived in Pennington County, SD in 2024.
Population estimates, 2000–2024
What are Pennington County, SD’s age demographics?
About 24,300 Pennington County residents are aged 65 and older in 2024. That represents 21% of its population. For comparison, the age group represents 18.9% of South Dakota’s population and 18% in the US overall.
Another 25,100 Pennington County residents, or 21.7% of the population, were children under 18. For comparison, the age group represents 24% of South Dakota’s population and 21.6% in the US overall.
A higher share of Pennington County, SD's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Pennington County, SD’s racial and ethnic demographics?
Non-Hispanic white residents make up 78.9% of the Pennington County, SD population, higher than the national share of 57.5%. Pennington County also has a larger share of people identifying as non-Hispanic American Indian and Alaska Native (8.6%) than the US overall (0.72%).
In contrast, Pennington County’s Hispanic population accounts for 6.1%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 1.3% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Pennington County, SD has a higher share of a non-Hispanic two or more races population than South Dakota as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Pennington County, SD is Rapid City with about 79,900 residents in 2024.
Cities and towns in Pennington County, SD ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Rapid City | 79,894 |
| 2. | Central Pennington UT | 14,899 |
| 3. | Box Elder (pt.) | 8,828 |
| 4. | Mount Rushmore UT | 4,735 |
| 5. | Rapid City East UT | 2,375 |
| 6. | West Pennington UT | 1,634 |
| 7. | Hill City | 937 |
| 8. | Wall | 672 |
| 9. | New Underwood | 610 |
| 10. | East Central Pennington UT | 389 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
