Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rapid City | 1 | 80,896 | 74,928 | 1.88% | 1,469 | 55.1 | City |
| Box Elder | 2 | 14,512 | 11,935 | 4.64% | 984 | 14.8 | City |
| Rapid Valley | 3 | 7,168 | 8,553 | -1.08% | 1,108 | 6.5 | CDP |
| Green Valley | 4 | 1,424 | 1,252 | 2.59% | 371 | 3.8 | CDP |
| Hill City | 5 | 978 | 877 | 2.62% | 745 | 1.3 | City |
| Wall | 6 | 684 | 698 | -0.58% | 260 | 2.6 | Town |
| New Underwood | 7 | 615 | 593 | 0.82% | 422 | 1.5 | City |
| Keystone | 8 | 240 | 244 | -0.41% | 80 | 3.0 | Town |
| Hill View Heights | 9 | 225 | 65 | 1.81% | 103 | 2.2 | CDP |
| Quinn | 10 | 64 | 63 | 0% | 53 | 1.2 | Town |
| Wasta | 11 | 61 | 63 | -1.61% | 318 | 0.2 | Town |
| Caputa | 12 | 34 | 0 | 9.68% | 116 | 0.3 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Rapid City is the largest city in Pennington County.
Caputa is the smallest city in Pennington County.
There are 12 cities in Pennington County, South Dakota.