Township · Illinois

Marissa Township, Illinois

Marissa Township, township, in St. Clair County, Illinois. Marissa Township had 2,149 residents on July 1, 2025 by the Census Bureau's estimate, down 5.4% since 2020; the 2020 Census counted 2,260 and the ACS 2020-2024 5-year estimates put it at 1,835 (±304). GEOID 1716346968.

Residents, July 2025 estimate

2,149

Census Bureau estimate (no margin published)
2020 Census count: 2,260 · ACS 2020-2024: 1,835 ±304

Median household income

$68,250

±$24,721 (90% margin)
Illinois: $83,390

Median home value

$113,200

±$36,779 (90% margin)
Illinois: $263,300

Median gross rent

$604

±$197 (90% margin)
Illinois: $1,274

Where is Marissa Township and what county is it in?

Marissa Township is a township in St. Clair County, Illinois. It covers 34.4 square miles of land, 66 residents per square mile in 2020.

One place lies inside Marissa Township: Marissa (village, 1,833 in 2020).

Marissa Township is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).

Marissa Township (marked with a dot) in St. Clair County, Illinois. Boundaries: Census Bureau 2024.

Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files

How many people live in Marissa Township, and is it growing?

The Census Bureau estimates that 2,149 people lived in Marissa Township on July 1, 2025, down 5.4% since 2020, a steeper fall than Illinois's (−0.8%). The 2020 Census counted 2,260 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 1,835 (±304).

  • July 2020→2021 −26 (2,239)
  • 2021→2022 −30 (2,209)
  • 2022→2023 −25 (2,184)
  • 2023→2024 −17 (2,167)
  • 2024→2025 −18 (2,149)
ACS 2020-2024 5-year estimates (counts) with the change from 2015-2019
MeasureMarissa TownshipSt. Clair CountyIllinoisChange since 2015-2019
Total population1,835±304253,69412,694,798no clear change
Households804±105100,8465,036,449no clear change
Average household size2.28±0.272.472.46no clear change
Housing units1,075±137115,6305,457,452no clear change

Marissa Township's population since 2000

From 2,664 in 2000 to 2,149 in 2025: down 19.3%. The 2000, 2010 and 2020 figures are census counts, each for Marissa Township as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. 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 2,664
  • 2005 (estimate) 2,535
  • 2010 Census 2,468
  • 2015 (estimate) 2,336
  • 2020 Census 2,260
  • 2025 (estimate) 2,149

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); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov

Who lives in Marissa Township?

The median resident of Marissa Township is 42.0 years old; 19.2% are under 18 and 20.1% are 65 or older. The largest group is non-Hispanic white residents at 88.4%, then non-Hispanic residents of two or more races at 8.0%.

Age, origin, education and moves, ACS 2020-2024 5-year estimates. Race groups are non-Hispanic; Hispanic includes any race.
MeasureMarissa TownshipSt. Clair CountyIllinoisChange since 2015-2019
Median age42.0±6.539.939.0−9.6
Under 18 years19.2%±5.4 pts23.0%21.8%–
65 years and over20.1%±7.0 pts17.3%17.0%–
Male46.0%±5.5 pts48.5%49.4%–
Hispanic or Latino (any race)3.3%±2.8 pts5.1%18.8%–
White alone, not Hispanic88.4%±6.6 pts59.1%58.1%−11.2 pts
Black or African American alone, not Hispanic0.0%±2.0 pts27.7%13.3%–
Asian alone, not Hispanic0.0%±2.0 pts1.6%5.9%–
American Indian and Alaska Native alone, not Hispanic0.3%±0.4 pts0.2%0.1%–
Native Hawaiian and Other Pacific Islander alone, not Hispanic0.0%±2.0 pts0.0%0.0%–
Two or more races, not Hispanic8.0%±6.2 pts5.8%3.4%–
Some other race alone, not Hispanic0.0%±2.0 pts0.5%0.4%–
Born outside the United States0.3%±0.5 pts3.3%14.7%–
Speak a language other than English at home (age 5+)0.7%±0.7 pts5.0%24.0%–
Civilian veterans (age 18+)12.1%±4.9 pts11.5%4.8%–
With a disability21.7%±7.4 pts15.2%12.1%–
No health insurance coverage2.7%±1.8 pts5.1%6.9%–
High school graduate or higher (age 25+)98.3%±1.3 pts93.5%90.5%–
Bachelor's degree or higher (age 25+)9.8%±3.7 pts31.8%37.8%no clear change
Graduate or professional degree (age 25+)4.3%±2.9 pts13.8%15.3%–
Lived in the same house a year earlier96.7%±3.0 pts88.3%88.9%–
Moved from another state in the past year0.3%±0.5 pts3.0%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 Marissa Township earn?

Half of Marissa Township's 804 households earn less than $68,250 a year (±$24,721), against $73,854 in St. Clair County and $83,390 in Illinois. In 2015-2019 it was $57,748 in 2024 dollars; the margins of error cannot tell the two periods apart. 11.5% of residents live below the poverty line.

Income and poverty in 2024 dollars, ACS 2020-2024 5-year estimates; 2015-2019 dollars adjusted with the R-CPI-U-RS
MeasureMarissa TownshipSt. Clair CountyIllinoisChange since 2015-2019
Median household income$68,250±$24,721$73,854$83,390no clear change
Mean household income$78,604±$12,227$96,049$115,638–
Per capita income$35,007±$4,033$38,942$46,406no clear change
People below the poverty line11.5%±6.2 pts13.6%11.8%no clear change
Children under 18 below the poverty line12.4%±9.9 pts18.9%15.1%–
Households receiving SNAP33.1%±13.0 pts16.2%13.8%–
Households with a computer94.7%±3.3 pts94.2%95.2%–
Households with a broadband subscription85.1%±6.5 pts89.7%90.8%–

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 Marissa Township?

Owners occupy 83.0% of Marissa Township's occupied homes and renters 17.0%. The median owner-occupied home is valued at $113,200 by its owner (±$36,779). The median renter pays $604 a month including utilities, and 69.2% of renters pay 35% or more of their income on rent.

Housing, ACS 2020-2024 5-year estimates. Home values are owners' own estimates.
MeasureMarissa TownshipSt. Clair CountyIllinoisChange since 2015-2019
Median home value (owner-occupied)$113,200±$36,779$180,300$263,300no clear change
Median gross rent$604±$197$1,090$1,274no clear change
Renters paying 35% or more of income on rent69.2%±24.9 pts39.8%39.0%+32.3 pts
Median monthly owner costs, with a mortgage$1,361±$382$1,645$1,987–
Owner-occupied homes83.0%±8.9 pts68.4%67.1%no clear change
Renter-occupied homes17.0%±8.9 pts31.6%32.9%–
Housing units1,075±137115,6305,457,452no clear change
Homeowner vacancy rate0.0%±5.4 pts1.1%1.0%–
Rental vacancy rate5.5%±13.8 pts4.7%5.0%–
Single-family detached homes76.7%±8.1 pts72.1%58.2%–
Mobile homes13.6%±6.6 pts4.4%2.3%–
Built 2020 or later0.0%±3.4 pts0.9%0.7%–
Built 2010 to 20190.8%±1.2 pts7.3%5.0%–
Built 1939 or earlier25.1%±7.2 pts13.5%20.2%–
Households with no vehicle11.8%±10.2 pts7.5%11.0%–

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 do people in Marissa Township work and get to work?

82.7% of Marissa Township's workers drive alone and 8.0% work from home. The average trip to work takes 29.2 minutes.

Work and commuting, ACS 2020-2024 5-year estimates (workers 16 and over)
MeasureMarissa TownshipSt. Clair CountyIllinoisChange since 2015-2019
In the labor force (age 16+)61.8%±7.1 pts63.4%65.0%–
Unemployment rate9.8%±7.3 pts6.0%5.8%–
Drove alone to work82.7%±7.2 pts75.4%65.9%–
Carpooled8.8%±6.2 pts8.1%7.8%–
Public transportation0.0%±4.6 pts1.6%5.8%–
Walked0.5%±1.0 pts1.5%2.8%–
Worked from home8.0%±4.0 pts12.4%15.9%–
Mean travel time to work29.2 min±4.024.0 min27.8 minno 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 census tracts are in Marissa Township?

No census tract lies mostly in Marissa Township; 1 tract reaches into it (2020 census blocks).

Census tracts in Marissa Township, ACS 2020-2024 5-year estimates
TractResidents, 2020-2024Median household incomeMedian home valueShare of tract in Marissa Township
Tract 5040.02St. Clair County5,136 $78,235 $167,20035%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Marissa Township) · Census block assignment files

How does Marissa Township compare with other places in Illinois?

By the Census Bureau's July 2025 estimates, Marissa Township is the 4,582nd-most populous of the 16,079 U.S. towns and townships that have one and the 412th-most populous of 1,407 in Illinois.

Marissa Township ranks 893rd of 1,380 places in Illinois with 1,000 or more residents and a reliable estimate, by median household income.

Marissa Township's rank in Illinois (1 = highest): by population among the state's towns and townships with a 2025 estimate; by the other measures among places of 1,000+ residents with a reliable estimate
MeasureRankOf
Population, July 2025 estimate412th1,407
Growth 2020-2025 (PEP)1,316th1,347
Residents per square mile1,094th1,383
Median household income893rd1,380
Per capita income890th1,383
Median home value1,073rd1,379
Median gross rent1,238th1,280
Poverty rate477th1,119
Bachelor's degree or higher1,332nd1,369
Median age585th1,383
Owner-occupied share437th1,382
Work from home747th1,015
Travel time to work334th1,382

Marissa Township's figures with every place in Illinois (CSV)

Every place in Illinois, sortable · Compare Marissa Township with other places

Source: PlainCities ranks computed 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 reliable are the figures for Marissa Township?

22 of the 57 figures for Marissa Township on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.

The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation

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 Marissa Township 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.