Marshall County's 2026 population is estimated at 4,469, reflecting a 0.83% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Marshall County is the 37th largest county in South Dakota. The 2010 population was 4,643 and has grown -3.75% since 2010.
Data after 2023 is projected based on recent change
Overall: 42.5 years
Female: 45.1 years
Male: 40.6 years
There are 3,287 adults, (1,009 of whom are seniors) in Marshall County.
Female: 2,044 (47.1%)
Male: 2,300 (52.9%)
The racial composition of Marshall County includes 84.48% White, 5.87% Native American, and smaller percentages for other race, Black or African American, Asian and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 3,670 | 84.48% |
| Two or more races | 279 | 6.42% |
| Native American | 255 | 5.87% |
| Other race | 113 | 2.6% |
| Black or African American | 19 | 0.44% |
| Asian | 8 | 0.18% |
Marshall County 's average per capita income is $46,820. Household income levels show a median of $78,156. The poverty rate stands at 6.06%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $110,250 | - |
| Families | $106,382 | $133,762 |
| Households | $78,156 | $103,822 |
| Non Families | $38,813 | $43,595 |
Average Income
Median Household Income
Poverty Rate