St. Mary Parish, Louisiana
Located in Louisiana, St. Mary Parish has a population of 47,828 residents and a median age of 39.7 years, making it the #1,044 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 20.8%. The median home value is $138,900, and the median household income is $52,576, which is 30% below the national median.
Demographics
St. Mary Parish has a population of 47,828, making it the #1,044 most populous county in the US. The median age is 39.7 years, which is 2.1% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in St. Mary Parish is $52,576, ranking #2,626 out of 3,222 counties — 30.0% below the national median. The poverty rate is 20.8% and unemployment stands at 5.4%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in St. Mary Parish is $138,900 (-50.7% vs national). Renters pay a median of $848/mo and the homeownership rate is 68.6%.
Median Home Value Trend
Rankings →Household Type
Education
In St. Mary Parish, 13.6% of adults age 25+ hold a bachelor's degree or higher, which is 59.5% below the national average, ranking #2,970 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in St. Mary Parish is 71.8 years. 28.0% of adults report poor or fair health and 9.3% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
24.8% of adults in St. Mary Parish smoke , 44.6% are obese , and 19.4% report excessive drinking. The drug overdose death rate is 48.5 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in St. Mary Parish is 11.5 per 100,000 and the suicide rate is 16.9 per 100,000. Motor vehicle deaths occur at a rate of 16.4 per 100,000.
Homicide Rate Trend
Families & Children
31.1% of children in St. Mary Parish live in poverty and the infant mortality rate is 5.7 per 1,000 live births. The teen birth rate is 32.9 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in St. Mary Parish is 62.9%. The mean commute time is 23.9 min, which is 13.5% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, St. Mary Parish voted Republican with a margin of 31.8%. The vote was 33.6% Dem / 65.4% Rep. Compared to 2020, the margin shifted 2.6 toward Republicans .
Vote Share Over Time
About St. Mary Parish, Louisiana
St. Mary Parish, Louisiana has a total population of 47,828, making it the 1,044th most populous county in the United States. The median age in St. Mary Parish is 39.7 years, which is 2.1% above the national median of 38.9 years.
The median household income in St. Mary Parish is $52,576, which ranks #2,626 of 3,222 counties nationwide. This is 30.0% below the national median of $75,149. The poverty rate is 20.8%, higher than the national rate of 12.6%. The unemployment rate stands at 5.4%.
The median home value in St. Mary Parish is $138,900, 50.7% below the national median. Renters in St. Mary Parish pay a median gross rent of $848 per month. The homeownership rate is 68.6%, compared to the national rate of 64.4%.
In St. Mary Parish, 13.6% of residents aged 25 and older hold a bachelor's degree or higher, 59.5% below the national average of 33.7%. Health insurance coverage stands at 91.5% of the population. The average commute time for workers is 23.9 min.
St. Mary Parish is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 53.4% of the population, followed by Black (non-Hispanic) (28.8%) and Hispanic or Latino (9.8%).
All data for St. Mary Parish, Louisiana comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.