St. Mary's County, Maryland Demographics 2026

Population Overview

St. Mary's County is located in Maryland with a total population of 114,372. It is the 12th most populous county out of 24 in Maryland.

Age Demographics

The median age in St. Mary's County is 37.0 years. This is 6% lower than the state median of 39.3 years.

Economy, Income & Housing

The median household income in St. Mary's County is $114,580. This is 13% higher than the state median of $101,652. Compared to the national median of $78,538, household income here is 46% higher. The poverty rate stands at 7.4%. This is 20% lower than the state poverty rate of 9.3%. The unemployment rate is 3.9%. This is 22% lower than the state rate of 4.9%. The median home value is $390,900. Housing costs are 2% lower than the state median of $397,700. The home-value-to-income ratio is 3.4x. 72.7% of occupied housing units are owner-occupied. This homeownership rate is 8% higher than the state average of 67.5%.

Race & Ethnicity

The largest racial or ethnic group in St. Mary's County is White (non-Hispanic), making up 71.0% of the population. Black or African American residents account for 14.6%. The Hispanic or Latino population (5.9%) is well below the state average of 12.1%. The Asian population (2.5%) is well below the state average of 6.4%.

Education

35.1% of residents aged 25 and older hold a bachelor's degree or higher. This is 18% lower than the state rate of 42.7%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 92.4%. Notably, 15.1% of adults hold a graduate or professional degree, indicating a highly educated workforce.