St. Mary Parish, Louisiana Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 22nd-largest in Louisiana
The population of St. Mary Parish, Louisiana is 48,455 as of the 2023 American Community Survey, making it the 22nd-largest county in Louisiana. The median household income is $51,768, the median home value is $128,000, and the median age is 39.7.
The population of St. Mary Parish has declined 14.2% since 2010 (54,553 → 46,799), a -1.09% annualized rate.
48,455
Population
-1.09%
Annual growth
87
People / sq mi
$51,768
Median Income
$128,000
Median Home Value
St. Mary Parish covers 559 sq mi of land at 86.8 people per square mile.
About St. Mary Parish, LA
St. Mary Parish is a county in Louisiana with a population of 48,455. It ranks #22 among counties in Louisiana by population. The median age is 39.7, in line with the national median. The population is 49.0% male and 51.0% female.
The median household income in St. Mary Parish is $51,768, below the US median of $74,580. 18.6% of residents live below the federal poverty level. Home values sit at a median of $128,000, with monthly rent averaging $839. The homeownership rate of 69.8% is higher than the national rate of 64.8%.
Educational attainment in St. Mary Parish reflects 13.1% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 5.2% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 24.7 minutes each way.
St. Mary Parish Population History (2010-2024)
The county of St. Mary Parish had a population of 54,553 in 2010 and 46,799 in 2024, a -14.2% growth over 14 years. The peak was 54,553 in 2010. Average annual growth rate: -1.09%.
46,799
Population (2024)
54,553
Population (2010)
54,553
Peak (2010)
-1.09%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 54,553 |
| 2011 | 54,199 |
| 2012 | 53,583 |
| 2013 | 53,608 |
| 2014 | 53,302 |
| 2015 | 52,908 |
| 2016 | 52,064 |
| 2017 | 50,673 |
| 2018 | 49,739 |
| 2019 | 49,294 |
| 2020 | 49,155 |
| 2021 | 48,240 |
| 2022 | 47,816 |
| 2023 | 47,131 |
| 2024 | 46,799 |
Race & Ethnicity
| White | 56.1% |
| Black or African American | 29.1% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.8% |
| Two or More Races | 0.0% |
Age & Sex
39.7
Median Age
51.0%
Female
49.0%
Male
18.0%
Age 65+
Age Distribution
Children (under 15): 20.3% · Seniors (65+): 18.0%
Income & Poverty
| Median household income | $51,768$-8,255 vs state |
| Mean household income | $70,302 |
| Per-capita income | $28,157 |
| Poverty rate | 18.6%+4.4% vs state |
| Unemployment rate | 3.0% |
| Employment-to-population | 51.6% |
Top Industries by Employment
The largest employment sector in St. Mary Parish is professional & business services, accounting for 22.1% of workers.
How residents commute
0.0%
Drive alone
1.3%
Carpool
84.1%
Public transit
5.2%
Work from home
24.7 min
Avg commute
Housing
$128,000$-80,700 vs state
Median home value
$839
Median rent
69.8%
Homeownership rate
22,510
Total housing units
83.1%
Occupied
16.9%
Vacant
30.2%
Renter-occupied
Social & access
93.2%
With health insurance
87.3%
With broadband internet
10.2%
Foreign-born
5.1%
Veterans (18+)
16.2%
With a disability
90.1%
Speak language other than English at home
Education
80.6%
High School+
13.1%
Bachelor's+
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Frequently Asked Questions
St. Mary Parish, Louisiana has a population of 48,455 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 22nd-largest county in Louisiana. Population density is 87 people per square mile.
The population of St. Mary Parish has declined 14.2% since 2010 (54,553 → 46,799), a -1.09% annualized rate.
The median household income in St. Mary Parish, Louisiana is $51,768, with mean (average) household income of $70,302 and per-capita income of $28,157. 18.6% of residents live below the federal poverty level.
In St. Mary Parish, the largest racial and ethnic groups are White (56.1%), Black or African American (29.1%), Hispanic or Latino (2.8%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in St. Mary Parish, Louisiana is 39.7 years. Residents are 51.0% female and 49.0% male.
The median home value in St. Mary Parish is $128,000 and median monthly rent is $839. 69.8% of occupied housing units are owner-occupied. The county has 22,510 total housing units, 16.9% of which are vacant.
The largest employment sector in St. Mary Parish, Louisiana is professional, scientific, and management services, employing 22.1% of workers. The unemployment rate is 3.0%.
New Orleans is among the largest cities associated with St. Mary Parish, Louisiana, with a population of 376,035.
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.