County · Louisiana

St. Mary Parish, Louisiana

St. Mary Parish, Louisiana. St. Mary Parish had 46,552 residents in 2025 by the Census Bureau's estimate, down 5.8% since 2020, a steeper fall than Louisiana's (−0.9%). It holds 12 places (5 cities, villages and boroughs and 7 census-designated) and 17 census tracts. GEOID 22101.

St. Mary Parish is the county of the Morgan City, LA micropolitan statistical area (the Census Bureau's July 2023 delineation).

Residents, July 2025 estimate

46,552

Census Bureau estimate (no margin published)
2020 Census count: 49,406 · ACS 2020-2024: 47,828

Median household income

$52,576

±$3,030 (90% margin)
Louisiana: $60,756

Median home value

$138,900

±$8,393 (90% margin)
Louisiana: $216,500

Median gross rent

$848

±$36 (90% margin)
Louisiana: $1,064

How many people live in St. Mary Parish, and is it growing?

The 2020 Census counted 49,406 residents in St. Mary Parish. The Census Bureau estimates 46,552 for July 1, 2025, down 5.8% since 2020, a steeper fall than Louisiana's (−0.9%). The 2020-2024 American Community Survey puts the population at 47,828 over 559 square miles of land.

July 2020→2021 −910 (48,239)
2021→2022 −339 (47,900)
2022→2023 −664 (47,236)
2023→2024 −263 (46,973)
2024→2025 −421 (46,552)

St. Mary Parish in Louisiana. Boundaries: Census Bureau 2024.

Counts, ACS 2020-2024 5-year estimates, with the change from 2015-2019
Measure	St. Mary Parish	Louisiana	Change since 2015-2019
Total population	47,828	4,611,961	−3,140
Households	18,463±468	1,804,780	−1,393
Average household size	2.55±0.06	2.49	no clear change
Housing units	22,507±85	2,108,902	−997

St. Mary Parish's population since 2000

From 53,500 in 2000 to 46,552 in 2025: down 13.0%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.

2000 Census 53,500
2005 (estimate) 53,015
2010 Census 54,650
2015 (estimate) 52,908
2020 Census 49,406
2025 (estimate) 46,552

Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov

What cities and towns are in St. Mary Parish?

St. Mary Parish holds 12 places: 5 cities, villages and boroughs (incorporated places) and 7 census-designated places. The largest is Morgan City with 10,757 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.

Places in St. Mary Parish, ACS 2020-2024 5-year estimates. Ring: estimate with a coefficient of variation over 40%.

Morgan City	city	11,472	11,064±42	$56,474	$155,200	17.4%	100%
Franklin	city	6,728	6,461±30	$39,518	$104,400	27.3%	100%
Patterson	city	5,931	5,744±19	$49,886	$160,400	22.9%	100%
Berwick	town	4,771	4,607±21	$51,580	$212,400	18.6%	100%
Bayou Vista	CDP	4,213	3,842±512	$40,500	$144,700	24.6%	100%
Amelia	CDP	2,132	1,712±347	$55,472	$87,500	18.0%	100%
Baldwin	town	1,762	1,962±446	$31,669	$129,400	26.9%	100%
Charenton	CDP	1,699	1,440±351	$63,463	$122,400	12.3%	100%
SorrelGEOID 2271190	CDP	711	564±254	$62,578	not published	15.1%	100%
Centerville	CDP	499	685±353	$74,509	$320,400	24.5%	100%
SiracusavilleGEOID 2270675	CDP	297	515±296	$78,085	$95,000	0.0%	100%
GlencoeGEOID 2229150	CDP	132	144±123	$30,742	$10,000 or less	6.9%	100%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov

Who lives in St. Mary Parish?

The median resident of St. Mary Parish is 39.7 years old; 24.5% are under 18 and 18.3% are 65 or older. The largest group is non-Hispanic white residents at 53.4%, then non-Hispanic Black residents at 28.8%. 5.0% of residents were born outside the United States.

Age, origin and education, ACS 2020-2024 5-year estimates. Race groups are non-Hispanic; Hispanic includes any race.
Measure	St. Mary Parish	Louisiana	Change since 2015-2019
Median age	39.7±0.6	38.0	no clear change
Under 18 years	24.5%	23.5%	–
65 years and over	18.3%±0.3 pts	16.7%	–
Hispanic or Latino (any race)	9.8%	7.2%	+2.8 pts
White alone, not Hispanic	53.4%±0.5 pts	55.7%	−2.7 pts
Black or African American alone, not Hispanic	28.8%±1.1 pts	30.5%	−1.5 pts
Asian alone, not Hispanic	1.0%±0.3 pts	1.7%	−0.4 pts
American Indian and Alaska Native alone, not Hispanic	1.5%±0.2 pts	0.4%	–
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0.0%±0.1 pts	0.1%	–
Two or more races, not Hispanic	5.2%±1.2 pts	3.8%	–
Some other race alone, not Hispanic	0.3%±0.2 pts	0.5%	–
Born outside the United States	5.0%±0.6 pts	4.9%	no clear change
Speak a language other than English at home (age 5+)	10.0%±1.0 pts	8.5%	–
Civilian veterans (age 18+)	5.1%±0.9 pts	6.1%	–
With a disability	16.7%±1.2 pts	16.3%	–
No health insurance coverage	8.5%±1.2 pts	7.8%	no clear change
High school graduate or higher (age 25+)	80.3%±1.9 pts	87.3%	–
Bachelor's degree or higher (age 25+)	13.6%±1.7 pts	27.0%	+3.4 pts
Graduate or professional degree (age 25+)	4.1%±1.1 pts	10.1%	–
Moved from another state in the past year	1.1%±0.7 pts	1.6%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov

What do households in St. Mary Parish earn?

Half of St. Mary Parish's 18,463 households earn less than $52,576 a year (±$3,030), against $60,756 in Louisiana. In 2015-2019 it was $49,825 in 2024 dollars; the margins of error cannot tell the two periods apart. 20.8% of residents live below the poverty line.

Income and poverty in 2024 dollars, ACS 2020-2024 5-year estimates
Measure	St. Mary Parish	Louisiana	Change since 2015-2019
Median household income	$52,576±$3,030	$60,756	no clear change
Mean household income	$71,245±$4,144	$87,038	–
Per capita income	$28,265±$1,551	$35,038	no clear change
People below the poverty line	20.8%±2.6 pts	18.9%	no clear change
Children under 18 below the poverty line	27.1%±5.1 pts	25.4%	no clear change
Households receiving SNAP	22.8%±2.4 pts	17.3%	–
Households with a broadband subscription	87.4%±2.2 pts	86.6%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What does housing cost in St. Mary Parish?

Owners occupy 68.6% of St. Mary Parish's occupied homes and renters 31.4%. The median owner-occupied home is valued at $138,900 by its owner (±$8,393). The median renter pays $848 a month including utilities, and 41.5% of renters pay 35% or more of their income on rent.

Housing, ACS 2020-2024 5-year estimates
Measure	St. Mary Parish	Louisiana	Change since 2015-2019
Median home value (owner-occupied)	$138,900±$8,393	$216,500	no clear change
Median gross rent	$848±$36	$1,064	−$113
Renters paying 35% or more of income on rent	41.5%±6.7 pts	46.3%	no clear change
Median monthly owner costs, with a mortgage	$1,420±$44	$1,604	–
Owner-occupied homes	68.6%±2.5 pts	67.4%	+7.9 pts
Housing units	22,507±85	2,108,902	−997
Homeowner vacancy rate	1.0%±0.8 pts	1.3%	–
Rental vacancy rate	8.3%±3.1 pts	7.8%	–
Single-family detached homes	68.9%±2.1 pts	65.3%	–
Mobile homes	17.8%±1.9 pts	12.6%	–
Built 2020 or later	0.4%±0.2 pts	1.8%	–
Built 1939 or earlier	6.0%±1.3 pts	6.1%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov

How many new homes is St. Mary Parish building?

Builders took permits for 40 new housing units across St. Mary Parish in 2025 (38 single-family), 0.9 per 1,000 residents.

2019 19 units
2020 22 units
2021 69 units
2022 12 units
2023 34 units
2024 47 units
2025 40 units

Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey

How do people in St. Mary Parish get to work?

84.7% of St. Mary Parish's workers drive alone and 5.5% work from home. The average trip to work takes 23.2 minutes. The unemployment rate in 2020-2024 averaged 5.4%.

Work and commuting, ACS 2020-2024 5-year estimates
Measure	St. Mary Parish	Louisiana	Change since 2015-2019
In the labor force (age 16+)	54.2%±2.0 pts	59.3%	–
Unemployment rate	5.4%±1.8 pts	6.3%	−3.3 pts
Drove alone to work	84.7%±1.9 pts	78.6%	–
Carpooled	7.6%±1.4 pts	8.7%	–
Public transportation	0.0%±0.2 pts	0.9%	–
Walked	1.4%±0.9 pts	1.8%	–
Worked from home	5.5%±1.6 pts	8.1%	+3.1 pts
Mean travel time to work	23.2 min±2.2	25.7 min	no clear change

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What are St. Mary Parish's census tracts?

St. Mary Parish is divided into 17 census tracts. Among those with a reliable estimate, median household income runs from $31,637 (Tract 412) to $78,798 (Tract 409).

Census tracts of St. Mary Parish, ACS 2020-2024 5-year estimates; sort by any column

Tract 40122101040100	Amelia (24%)	2,565	2,345±453	$58,306	$94,900	$592	13.6%
Tract 40222101040200	Morgan City (97%)	4,738	4,454±521	$70,038	$172,500	$1,285	9.5%
Tract 40322101040300	Morgan City (96%)	2,912	2,612±455	$66,250	$123,400	$878	13.7%
Tract 40422101040400	Morgan City (97%)	3,690	3,880±577	$34,496	$107,500	$884	28.9%
Tract 40522101040500	Berwick (84%)	4,806	4,607±21	$51,580	$212,400	$493	18.6%
Tract 40622101040600	Bayou Vista (88%)	4,218	3,842±512	$40,500	$144,700	$864	24.6%
Tract 40722101040700	Patterson (95%)	3,633	3,097±398	$40,641	$120,000	$813	23.8%
Tract 40822101040800	Patterson (24%)	4,773	5,076±578	$73,382	$164,100	$1,052	16.7%
Tract 40922101040900	Franklin (8%)	2,912	3,477±593	$78,798	$168,900	$645	31.4%
Tract 41022101041000	Charenton (22%)	3,678	3,263±444	$62,847	$120,200	$1,059	14.5%
Tract 41122101041100	Franklin (9%)	1,478	1,120±315	$52,961	$88,300	not published	16.5%
Tract 41222101041200	Baldwin (83%)	1,546	1,804±428	$31,637	$125,200	$953	29.2%
Tract 41322101041300	Franklin (65%)	1,922	1,884±349	$35,997	$93,200	$807	34.4%
Tract 41422101041400	Franklin (64%)	3,142	2,782±414	$63,065	$66,200	$855	17.5%
Tract 41522101041500	Franklin (87%)	1,710	1,881±310	$49,432	$146,700	$775	22.7%
Tract 41622101041600	Franklin (96%)	1,683	1,704±313	$37,900	$95,400	$745	30.6%
Tract 990022101990000	–	0	0±14	not published	not published	not published	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov

How does St. Mary Parish compare with Louisiana's other counties?

St. Mary Parish's rank among Louisiana's counties with a reliable estimate (1 = highest)
Measure	Rank
Population	23rd of 64
Growth 2020-2025	50th of 64
Residents per square mile	23rd of 64
Median household income	35th of 64
Median home value	42nd of 64
Median gross rent	32nd of 64
Poverty rate	33rd of 64
Bachelor's degree or higher	53rd of 64
Median age	29th of 64

Every county in Louisiana

Source: PlainCities ranks from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections

Not on this page: crime, weather and schools for St. Mary Parish are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.