St. Mary's County's estimated 2026 population is 118,449 with a growth rate of 0.84% in the past year according to the most recent United States census data. St. Mary's County is the 12th largest county in Maryland. The 2010 population was 105,772 and has seen a growth of 11.99% since that time.
Data after 2023 is projected based on recent change
The racial composition of St. Mary's County includes 72.31% White, 14.75% Black or African American, and smaller percentages for Asian, other race, Native American and multiracial populations.
White (72.31%)
Black or African American (14.75%)
Two or more races (8.27%)
Asian (2.57%)
Other race (2%)
Native American (0.1%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 82,702 | 72.31% |
| Black or African American | 16,874 | 14.75% |
| Two or more races | 9,453 | 8.27% |
| Asian | 2,935 | 2.57% |
| Other race | 2,290 | 2% |
| Native American | 118 | 0.1% |
Married
Widowed
Divorced
Separated
Never Married
St. Mary's County's average per capita income is $72,426. Household income levels show a median of $114,580. The poverty rate stands at 7.45%.
Name | Median | Mean |
|---|---|---|
| Married Families | $159,358 | $178,750 |
| Families | $133,566 | $155,397 |
| Households | $114,580 | $138,624 |
| Non Families | $75,133 | $88,217 |
Average Income
Median Household Income
Poverty Rate