Village · Illinois
Williamson, Illinois
Williamson, village, in Madison County, Illinois. Williamson had 175 residents on July 1, 2025 by the Census Bureau's estimate, down 3.3% since 2020; the 2020 Census counted 183 and the ACS 2020-2024 5-year estimates put it at 160 (±51). GEOID 1781815.
Residents, July 2025 estimate
175
Census Bureau estimate (no margin published)
2020 Census count: 183 · ACS 2020-2024: 160 ±51
Median household income
$57,841
±$20,044 (90% margin)
Illinois: $83,390
Median home value
$75,800
±$37,623 (90% margin)
Illinois: $263,300
Median gross rent
$863
±$316 (90% margin)
Illinois: $1,274
Where is Williamson and what county is it in?
Williamson is a village in Madison County, Illinois. It covers 1.2 square miles of land, 156 residents per square mile in 2020.
Williamson is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).
Williamson lies entirely within Olive Township, a township with its own local government (2020 census blocks).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Williamson, and is it growing?
The Census Bureau estimates that 175 people lived in Williamson on July 1, 2025, down 3.3% since 2020, a steeper fall than Illinois's (−0.8%). The 2020 Census counted 183 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 160 (±51).
| Measure | Williamson | Madison County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 160 ±51 | 264,238 | no clear change |
| Households | 81 ±26 | 110,134 | no clear change |
| Average household size | 1.98 ±0.31 | 2.35 | −0.55 |
| Housing units | 98 ±29 | 119,168 | no clear change |
Williamson's population since 2000
From 251 in 2000 to 175 in 2025: down 30.3%. The 2000, 2010 and 2020 figures are census counts, each for Williamson 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 Williamson?
The median resident of Williamson is 51.0 years old; 13.8% are under 18 and 25.0% are 65 or older. The largest group is non-Hispanic white residents at 89.4%, then non-Hispanic residents of two or more races at 5.6%.
| Measure | Williamson | Madison County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 51.0 ±11.3 | 40.2 | no clear change |
| Under 18 years | 13.8% ±8.0 pts | 21.3% | – |
| 65 years and over | 25.0% ±12.2 pts | 18.5% | – |
| Male | 46.9% ±8.8 pts | 48.9% | – |
| Hispanic or Latino (any race) | 5.0% ±5.4 pts | 4.3% | – |
| White alone, not Hispanic | 89.4% ±7.0 pts | 81.8% | −8.3 pts |
| Black or African American alone, not Hispanic | 0.0% ±20.7 pts | 7.7% | – |
| Asian alone, not Hispanic | 0.0% ±20.7 pts | 0.8% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±20.7 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±20.7 pts | 0.0% | – |
| Two or more races, not Hispanic | 5.6% ±5.0 pts | 5.0% | – |
| Some other race alone, not Hispanic | 0.0% ±20.7 pts | 0.2% | – |
| Born outside the United States | 0.6% ±1.2 pts | 2.2% | – |
| Speak a language other than English at home (age 5+) | 0.0% ±20.8 pts | 3.6% | – |
| Civilian veterans (age 18+) | 13.0% ±7.8 pts | 8.2% | – |
| With a disability | 27.5% ±16.2 pts | 15.8% | – |
| No health insurance coverage | 1.3% ±2.1 pts | 4.7% | – |
| High school graduate or higher (age 25+) | 75.8% ±16.6 pts | 93.9% | – |
| Bachelor's degree or higher (age 25+) | 5.6% ±4.5 pts | 31.0% | – |
| Graduate or professional degree (age 25+) | 0.0% ±25.6 pts | 11.2% | – |
| Lived in the same house a year earlier | 96.3% ±3.9 pts | 88.5% | – |
| Moved from another state in the past year | 1.3% ±1.8 pts | 2.1% | – |
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 Williamson earn?
Half of Williamson's 81 households earn less than $57,841 a year (±$20,044), against $75,793 in Madison County and $83,390 in Illinois. In 2015-2019 it was $66,150 in 2024 dollars; the margins of error cannot tell the two periods apart.
| Measure | Williamson | Madison County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $57,841 ±$20,044 | $75,793 | no clear change |
| Mean household income | $63,896 ±$16,904 | $98,419 | – |
| Per capita income | $32,692 ±$7,613 | $41,560 | no clear change |
| People below the poverty line | 19.6% ±14.1 pts | 11.1% | – |
| Children under 18 below the poverty line | 13.3% ±24.0 pts | 13.2% | – |
| Households receiving SNAP | 24.7% ±14.1 pts | 13.7% | – |
| Households with a computer | 86.4% ±17.0 pts | 94.9% | – |
| Households with a broadband subscription | 81.5% ±17.9 pts | 91.0% | – |
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 Williamson?
Owners occupy 67.9% of Williamson's occupied homes and renters 32.1%. The median owner-occupied home is valued at $75,800 by its owner (±$37,623). The median renter pays $863 a month including utilities.
| Measure | Williamson | Madison County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $75,800 ±$37,623 | $173,000 | no clear change |
| Median gross rent | $863 ±$316 | $1,024 | no clear change |
| Renters paying 35% or more of income on rent | 9.5% ±16.9 pts | 37.8% | – |
| Median monthly owner costs, with a mortgage | $1,141 ±$81 | $1,511 | – |
| Owner-occupied homes | 67.9% ±15.8 pts | 74.2% | no clear change |
| Renter-occupied homes | 32.1% ±15.8 pts | 25.8% | – |
| Housing units | 98 ±29 | 119,168 | no clear change |
| Homeowner vacancy rate | 9.8% ±15.8 pts | 1.0% | – |
| Rental vacancy rate | 0.0% ±62.5 pts | 4.1% | – |
| Single-family detached homes | 85.7% ±11.1 pts | 78.9% | – |
| Mobile homes | 12.2% ±10.8 pts | 2.2% | – |
| Built 2020 or later | 0.0% ±30.7 pts | 0.9% | – |
| Built 2010 to 2019 | 0.0% ±30.7 pts | 6.0% | – |
| Built 1939 or earlier | 42.9% ±16.8 pts | 14.6% | – |
| Households with no vehicle | 9.9% ±16.6 pts | 5.7% | – |
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 Williamson building?
Builders took permits for 0 new housing units in Williamson in 2025 (0 in single-family houses), 0.0 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 Williamson work and get to work?
86.9% of Williamson's workers drive alone. The average trip to work takes 30.5 minutes.
| Measure | Williamson | Madison County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 63.8% ±16.6 pts | 62.7% | – |
| Unemployment rate | 0.0% ±33.2 pts | 4.6% | – |
| Drove alone to work | 86.9% ±10.9 pts | 78.1% | – |
| Carpooled | 4.8% ±7.2 pts | 6.6% | – |
| Public transportation | 0.0% ±34.2 pts | 0.6% | – |
| Walked | 2.4% ±3.6 pts | 1.1% | – |
| Worked from home | 6.0% ±7.3 pts | 12.7% | – |
| Mean travel time to work | 30.5 min ±8.1 | 24.9 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 Williamson?
No census tract lies mostly in Williamson; 1 tract reaches into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 4038.02Madison County | 4,565 | $83,143 |
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 Williamson) · Census block assignment files
How does Williamson compare with other places in Illinois?
By the Census Bureau's July 2025 estimates, Williamson is the 16,892nd-most populous of the 19,476 U.S. incorporated places that have one and the 1,131st-most populous of 1,294 in Illinois.
Williamson is not ranked by income or the other survey measures: those rankings include places of 1,000 or more residents (2020 Census) with a reliable estimate.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 1,131st | 1,294 |
Williamson's figures with every place in Illinois (CSV)
Every place in Illinois, sortable · Compare Williamson 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 Williamson?
27 of the 57 figures for Williamson 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 Williamson 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 Williamson.