St. Mary's County's estimated 2025 population is 116,277 with a growth rate of 0.43% 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 9.93% 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, Native Hawaiian or Pacific Islander and multiracial populations.
White
Black or African American
Two or more races
Asian
Other race
Native American
Native Hawaiian or Pacific Islander
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% |
| Native Hawaiian or Pacific Islander | 0 | 0% |
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