How many people live in St. Mary Parish, LA?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 46,800 people living in St. Mary Parish, LA. That makes St. Mary Parish the 23rd-most populous parish in Louisiana. It is home to 1% of people living in the state.
46.8K
population of St. Mary Parish, LA (2024)
1%
County share of the Louisiana population (2024)
About 46,800 people lived in St. Mary Parish, LA in 2024.
Population estimates, 2000–2024
What are St. Mary Parish, LA’s age demographics?
About 9,200 St. Mary Parish, LA residents are aged 65 and older in 2024. That represents 19.8% of its population. For comparison, the age group represents 17.8% of Louisiana’s population and 18% in the US overall.
Another 11,600 St. Mary Parish residents, or 24.7% of the population, were children under 18. For comparison, the age group represents 23.3% of Louisiana’s population and 21.6% in the US overall.
A lower share of St. Mary Parish, LA's population is aged 25–44 than the US as a whole.
Population estimates by age group, (2024)
What are St. Mary Parish, LA’s racial and ethnic demographics?
Non-Hispanic Black or African American residents make up 30.2% of the St. Mary Parish, LA population, higher than the national share of 12.6%. St. Mary Parish, LA also has a larger share of people identifying as non-Hispanic American Indian and Alaska Native (1.9%) than the US overall (0.72%).
In contrast, St. Mary Parish’s Hispanic population accounts for 10.8%, below the 20% nationwide, and the non-Hispanic Asian population makes up 1.3% of the parish, compared with 6.5% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
St. Mary Parish, LA has a higher share of a Hispanic population than Louisiana as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in St. Mary Parish, LA is Morgan City with about 10,800 residents in 2024.
Cities and towns in St. Mary Parish, LA ranked by population
Population (2024), includes only portions within parish
| City or town | Population | |
|---|---|---|
| 1. | Morgan City (pt.) | 10,813 |
| 2. | Franklin | 6,284 |
| 3. | Patterson | 5,614 |
| 4. | Berwick | 4,495 |
| 5. | Baldwin | 1,665 |
| 6. | Balance of St. Mary Parish | 17,928 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
