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 distinguished by its share of foreign-born residents, 10.2% of the population. St. Mary Parish is a county in Louisiana with a population of 48,455. It ranks #22 among counties in Louisiana by population.
The typical household earns $51,768, below the US median of $78,538. The poverty rate, 18.6%, is among the steepest of comparable US counties and above the national 12.4%. Housing is relatively affordable, with a median home value of $128,000, with typical rent around $839.
St. Mary Parish is among the least college-educated US counties, at 13.1% — below the national 35.0%. Remote work is on the lower side here, at 5.2%, below the national 14.0%, and the average commute runs about 25 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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County rankings
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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Statewide data for Louisiana
Population, race, income, age, and trends across Louisiana
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.