Demographics of St. Mary Parish, Louisiana

St. Mary Parish, Louisiana had 46,552 people on July 1, 2025, by the Census Bureau’s estimate: −2,597 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

St. Mary Parish, in four figures

46,552
Population: July 1, 2025, Vintage 2025 estimate.; −5.3%
Change since July 2020: −2,597 people.; 39.7 ±0.6
Median age: ACS 2020–⁠2024.; $52,576 ±$3,030
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

St. Mary Parish, Louisiana's population shrank 5.3% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of St. Mary Parish, Louisiana's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

Source: The Census Bureau

About this chart

The figures

St. Mary Parish, Louisiana's population shrank 5.3% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of St. Mary Parish, Louisiana's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	49,149	100.0	100.0
2021	48,239	98.1	100.2
2022	47,900	97.5	100.7
2023	47,236	96.1	101.6
2024	46,973	95.6	102.5
2025	46,552	94.7	103.1

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Population of St. Mary Parish, Louisiana on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	49,149	−256	−25	+2	−213
2021	48,239	−910	−58	+46	−875
2022	47,900	−339	−135	+248	−458
2023	47,236	−664	−69	+246	−846
2024	46,973	−263	−44	+262	−484
2025	46,552	−421	−53	+96	−462

Age, 2020–2024

The median age is 39.7 ±0.6: for men 39.2 ±0.8 and for women 40.7 ±1.1. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in St. Mary Parish by age, ACS 2020–2024
Age	People	Share	Louisiana	United States
Under 5	3,171 ±106	6.6% ±0.2	6.2% ±<0.1	5.6% ±<0.1
5 to 17	8,526 ±583	17.8% ±1.2	17.3% ±0.1	16.3% ±<0.1
18 to 24	3,614 ±450	7.6% ±0.9	9.1% ±0.1	9.1% ±<0.1
25 to 44	11,233 ±600	23.5% ±1.3	26.6% ±0.1	26.9% ±<0.1
45 to 64	12,513 ±583	26.2% ±1.2	24.1% ±0.1	24.8% ±<0.1
65 and over	8,771 ±582	18.3% ±1.2	16.7% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $52,576 ±$3,030, and income per person $28,265 ±$1,551, in 2024 dollars. The median is $60,756 ±$408 in Louisiana and $80,734 ±$166 in the United States.

Households by income

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Households in St. Mary Parish by income, ACS 2020–2024
Household income	Households	Share	Louisiana	United States
Under $25,000	4,570 ±525	24.8% ±2.8	22.4% ±0.3	14.6% ±<0.1
$25,000 to $49,999	4,195 ±537	22.7% ±2.9	20.2% ±0.3	16.7% ±<0.1
$50,000 to $74,999	3,189 ±397	17.3% ±2.1	15.9% ±0.2	15.5% ±<0.1
$75,000 to $99,999	2,179 ±356	11.8% ±1.9	11.7% ±0.2	12.6% ±<0.1
$100,000 to $149,999	2,788 ±402	15.1% ±2.1	14.8% ±0.3	17.5% ±<0.1
$150,000 to $199,999	820 ±192	4.4% ±1.0	7.3% ±0.2	9.6% ±<0.1
$200,000 or more	722 ±207	3.9% ±1.1	7.8% ±0.2	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in St. Mary Parish by age, ACS 2020–2024
Age	Below poverty	Rate	Louisiana	United States
All ages	9,809 ±1,218	20.8% ±2.6	18.9% ±0.3	12.5% ±0.1
Under 18	3,164 ±512	27.1% ±4.0	25.4% ±0.5	16.1% ±0.1
18 to 59	4,337 ±732	18.7% ±3.0	17.7% ±0.3	11.6% ±0.1
60 and over	2,308 ±390	18.7% ±3.0	15.2% ±0.3	11.0% ±<0.1

Housing, 2020–2024

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Housing in St. Mary Parish, ACS 2020–2024
Measure	St. Mary Parish	Louisiana	United States
Housing units	22,507 ±85	2,108,902 ±333	143,775,355 ±10,234
Occupied	82.0% ±2.1	85.6% ±0.2	89.9% ±0.1
Vacant	18.0% ±2.1	14.4% ±0.2	10.1% ±0.1
Owner occupied	68.6% ±2.5	67.4% ±0.4	65.2% ±0.3
Renter occupied	31.4% ±2.5	32.6% ±0.3	34.8% ±0.1
Median home value	$138,900 ±$8,393	$216,500 ±$1,367	$332,700 ±$236
Median gross rent	$848 ±$36	$1,064 ±$8	$1,413 ±$2
Median year built	1976 ±1	1983 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in St. Mary Parish by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Louisiana	United States
Hispanic or Latino	4,705 ±0	9.8% ±<0.1	7.2% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	25,540 ±240	53.4% ±0.5	55.7% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	13,765 ±523	28.8% ±1.1	30.5% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	466 ±124	1.0% ±0.3	1.7% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	705 ±86	1.5% ±0.2	0.4% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 17	0% to < 0.1%	0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	36 to 224	0.1% to 0.5%	0.5% ±0.1	0.6% ±<0.1
Two or more races, not Hispanic	2,510 ±589	5.2% ±1.2	3.8% ±0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in St. Mary Parish by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Louisiana	United States
Born in the state	40,603 ±650	84.9% ±1.4	77.2% ±0.2	57.3% ±<0.1
Born in another state	4,442 ±603	9.3% ±1.3	17.2% ±0.2	26.9% ±<0.1
Born a citizen outside the states	414 ±204	0.9% ±0.4	0.7% ±<0.1	1.7% ±<0.1
Born abroad	2,369 ±297	5.0% ±0.6	4.9% ±0.1	14.1% ±<0.1
Naturalized citizens	826 ±212	1.7% ±0.4	2.0% ±0.1	7.4% ±<0.1
Not citizens	1,543 ±243	3.2% ±0.5	2.9% ±0.1	6.8% ±<0.1

St. Mary Parish among the counties of Louisiana

23rd of 64 by population, July 2025. Every one is listed on the Louisiana page.

Counties of Louisiana near St. Mary Parish in population, July 2025
County	July 2025	Change since 2020
Vermilion Parish	57,671	+1.3%
Acadia Parish	57,032	−0.8%
St. Martin Parish	51,106	−1.0%
St. Charles Parish	50,586	−3.7%
Lincoln Parish	48,360	+0.1%
St. Mary Parish	46,552	−5.3%
St. Bernard Parish	45,642	+4.1%
Vernon Parish	45,091	−7.3%
Washington Parish	44,937	−0.9%
St. John the Baptist Parish	39,875	−5.9%
Avoyelles Parish	37,941	−4.3%

Elsewhere on the site

Rankings this appears in

No. 3 Counties in Louisiana by Hispanic or Latino share
No. 4 Counties in Louisiana by foreign-born share
No. 14 Counties in Louisiana by poverty rate
No. 15 Counties in Louisiana by median age
No. 21 Counties in Louisiana by median rent
No. 23 Counties by population in Louisiana

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Compiled automatically from Census Bureau population estimates — counties and Puerto Rico municipios, with components of change and American Community Survey 5-year estimates — table-based Summary File by a checked SQL query · Editor: Kian O'Connor · How this site is built

Data retrieved September 25, 2026