St. Mary Parish's 2026 population is estimated at 46,135, reflecting a -0.71% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). St. Mary Parish is the 23rd largest parish in Louisiana. The 2010 population was 54,553 and has grown -15.43% since 2010.
Data after 2023 is projected based on recent change
Overall: 39.7 years
Female: 40.7 years
Male: 39.2 years
There are 36,131 adults, (8,771 of whom are seniors) in St. Mary Parish.
Female: 24,581 (51.4%)
Male: 23,247 (48.6%)
The racial composition of St. Mary Parish includes 56.87% White, 28.92% Black or African American, and smaller percentages for other race, Native American, Asian, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 27,202 | 56.87% |
| Black or African American | 13,832 | 28.92% |
| Two or more races | 4,229 | 8.84% |
| Other race | 1,361 | 2.85% |
| Native American | 731 | 1.53% |
| Asian | 466 | 0.97% |
| Native Hawaiian or Pacific Islander | 7 | 0.01% |
St. Mary Parish 's average per capita income is $39,311. Household income levels show a median of $52,576. The poverty rate stands at 20.79%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $88,924 | - |
| Families | $66,013 | $79,249 |
| Households | $52,576 | $71,245 |
| Non Families | $30,480 | $52,693 |
Average Income
Median Household Income
Poverty Rate