Village · Illinois
Dupo, Illinois
Dupo, village, mostly in St. Clair County (99.9% of its 2020 residents), with a part in Monroe County, Illinois. Dupo had 3,766 residents on July 1, 2025 by the Census Bureau's estimate, down 5.7% since 2020; the 2020 Census counted 3,996 and the ACS 2020-2024 5-year estimates put it at 3,879 (±16). GEOID 1721254.
Residents, July 2025 estimate
3,766
Census Bureau estimate (no margin published)
2020 Census count: 3,996 · ACS 2020-2024: 3,879 ±16
Median household income
$61,644
±$11,842 (90% margin)
Illinois: $83,390
Median home value
$113,800
±$12,105 (90% margin)
Illinois: $263,300
Median gross rent
$912
±$60 (90% margin)
Illinois: $1,274
Where is Dupo and what county is it in?
Dupo is a village mostly in St. Clair County (99.9% of its 2020 residents), with a part in Monroe County, Illinois. It covers 6.4 square miles of land, 624 residents per square mile in 2020.
Dupo is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).
Dupo lies mostly within Sugar Loaf Township, a township with its own local government (2020 census blocks).
| County | 2020 residents | Share |
|---|---|---|
| St. Clair County | 3,990 | 99.9% |
| Monroe County | 6 | 0.2% |
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Dupo, and is it growing?
The Census Bureau estimates that 3,766 people lived in Dupo on July 1, 2025, down 5.7% since 2020, a steeper fall than Illinois's (−0.8%). The 2020 Census counted 3,996 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 3,879 (±16).
| Measure | Dupo | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 3,879 ±16 | 253,694 | −59 |
| Households | 1,598 ±159 | 100,846 | no clear change |
| Average household size | 2.43 ±0.24 | 2.47 | no clear change |
| Housing units | 1,739 ±191 | 115,630 | no clear change |
Dupo's population since 2000
From 3,933 in 2000 to 3,766 in 2025: down 4.2%. The 2000, 2010 and 2020 figures are census counts, each for Dupo 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.
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 Dupo?
The median resident of Dupo is 42.9 years old; 20.0% are under 18 and 14.8% are 65 or older. The largest group is non-Hispanic white residents at 85.6%, then non-Hispanic residents of two or more races at 6.8%.
| Measure | Dupo | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 42.9 ±9.4 | 39.9 | no clear change |
| Under 18 years | 20.0% ±5.2 pts | 23.0% | – |
| 65 years and over | 14.8% ±3.9 pts | 17.3% | – |
| Male | 56.1% ±4.9 pts | 48.5% | – |
| Hispanic or Latino (any race) | 1.5% ±1.6 pts | 5.1% | – |
| White alone, not Hispanic | 85.6% ±6.7 pts | 59.1% | no clear change |
| Black or African American alone, not Hispanic | 5.5% ±4.2 pts | 27.7% | – |
| Asian alone, not Hispanic | 0.5% ±0.8 pts | 1.6% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±1.0 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±1.0 pts | 0.0% | – |
| Two or more races, not Hispanic | 6.8% ±4.5 pts | 5.8% | – |
| Some other race alone, not Hispanic | 0.0% ±1.0 pts | 0.5% | – |
| Born outside the United States | 0.7% ±0.9 pts | 3.3% | – |
| Speak a language other than English at home (age 5+) | 1.6% ±1.6 pts | 5.0% | – |
| Civilian veterans (age 18+) | 4.4% ±2.2 pts | 11.5% | – |
| With a disability | 14.7% ±4.2 pts | 15.2% | – |
| No health insurance coverage | 8.8% ±3.6 pts | 5.1% | no clear change |
| High school graduate or higher (age 25+) | 92.8% ±4.3 pts | 93.5% | – |
| Bachelor's degree or higher (age 25+) | 17.8% ±6.6 pts | 31.8% | no clear change |
| Graduate or professional degree (age 25+) | 6.7% ±4.2 pts | 13.8% | – |
| Lived in the same house a year earlier | 84.9% ±11.6 pts | 88.3% | – |
| Moved from another state in the past year | 2.6% ±1.9 pts | 3.0% | – |
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 Dupo earn?
Half of Dupo's 1,598 households earn less than $61,644 a year (±$11,842), against $73,854 in St. Clair County and $83,390 in Illinois. In 2015-2019 it was $49,607 in 2024 dollars; the margins of error cannot tell the two periods apart. 8.5% of residents live below the poverty line.
| Measure | Dupo | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $61,644 ±$11,842 | $73,854 | no clear change |
| Mean household income | $74,815 ±$10,386 | $96,049 | – |
| Per capita income | $31,137 ±$3,444 | $38,942 | no clear change |
| People below the poverty line | 8.5% ±3.9 pts | 13.6% | −11.7 pts |
| Children under 18 below the poverty line | 1.9% ±3.2 pts | 18.9% | – |
| Households receiving SNAP | 18.6% ±8.1 pts | 16.2% | – |
| Households with a computer | 98.1% ±1.9 pts | 94.2% | – |
| Households with a broadband subscription | 88.4% ±7.3 pts | 89.7% | – |
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 Dupo?
Owners occupy 65.4% of Dupo's occupied homes and renters 34.6%. The median owner-occupied home is valued at $113,800 by its owner (±$12,105). The median renter pays $912 a month including utilities.
| Measure | Dupo | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $113,800 ±$12,105 | $180,300 | +$15,714 |
| Median gross rent | $912 ±$60 | $1,090 | −$150 |
| Renters paying 35% or more of income on rent | 27.1% ±18.5 pts | 39.8% | – |
| Median monthly owner costs, with a mortgage | $1,210 ±$131 | $1,645 | – |
| Owner-occupied homes | 65.4% ±10.9 pts | 68.4% | no clear change |
| Renter-occupied homes | 34.6% ±10.9 pts | 31.6% | – |
| Housing units | 1,739 ±191 | 115,630 | no clear change |
| Homeowner vacancy rate | 0.0% ±3.4 pts | 1.1% | – |
| Rental vacancy rate | 0.0% ±6.6 pts | 4.7% | – |
| Single-family detached homes | 71.5% ±8.2 pts | 72.1% | – |
| Mobile homes | 11.0% ±5.1 pts | 4.4% | – |
| Built 2020 or later | 1.2% ±1.3 pts | 0.9% | – |
| Built 2010 to 2019 | 1.6% ±1.6 pts | 7.3% | – |
| Built 1939 or earlier | 21.9% ±9.5 pts | 13.5% | – |
| Households with no vehicle | 8.1% ±8.5 pts | 7.5% | – |
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 Dupo building?
Builders took permits for 1 new housing units in Dupo in 2025 (1 in single-family houses), 0.3 per 1,000 residents against 1.5 across Illinois.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Dupo work and get to work?
81.8% of Dupo's workers drive alone and 6.1% work from home. The average trip to work takes 25.6 minutes.
| Measure | Dupo | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 68.0% ±4.4 pts | 63.4% | – |
| Unemployment rate | 6.2% ±4.4 pts | 6.0% | – |
| Drove alone to work | 81.8% ±8.1 pts | 75.4% | – |
| Carpooled | 9.6% ±6.5 pts | 8.1% | – |
| Public transportation | 0.0% ±2.1 pts | 1.6% | – |
| Walked | 1.1% ±1.7 pts | 1.5% | – |
| Worked from home | 6.1% ±3.2 pts | 12.4% | – |
| Mean travel time to work | 25.6 min ±3.5 | 24.0 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 census tracts are in Dupo?
1 census tract lies mostly in Dupo, and 3 more reach into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 5031.02St. Clair County | 4,219 | $61,450 |
| Tract 5031.01St. Clair County | 2,672 | $112,740 |
| Tract 6001.04Monroe County | 5,076 | $136,113 |
| Tract 6001.02Monroe County | 4,654 | $112,838 |
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 Dupo) · Census block assignment files
How does Dupo compare with other places in Illinois?
By the Census Bureau's July 2025 estimates, Dupo is the 5,673rd-most populous of the 19,476 U.S. incorporated places that have one and the 382nd-most populous of 1,294 in Illinois.
Dupo ranks 1,059th of 1,380 places in Illinois with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 382nd | 1,294 |
| Growth 2020-2025 (PEP) | 1,328th | 1,347 |
| Residents per square mile | 751st | 1,383 |
| Median household income | 1,059th | 1,380 |
| Per capita income | 1,125th | 1,383 |
| Median home value | 1,064th | 1,379 |
| Median gross rent | 725th | 1,280 |
| Poverty rate | 679th | 1,119 |
| Bachelor's degree or higher | 1,014th | 1,369 |
| Median age | 478th | 1,383 |
| Owner-occupied share | 1,176th | 1,382 |
| Work from home | 894th | 1,015 |
| Travel time to work | 692nd | 1,382 |
Dupo's figures with every place in Illinois (CSV)
Every place in Illinois, sortable · Compare Dupo 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 Dupo?
21 of the 57 figures for Dupo 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 Dupo 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' public schools in Dupo.