Williamson County Flag

Williamson County

State:
Illinois
County Seat:
Marion

Williamson County's estimated 2025 population is 67,030 with a growth rate of 0.24% in the past year according to the most recent United States census data. Williamson County is the 22nd largest county in Illinois. The 2010 population was 66,440 and has seen a growth of 0.89% since that time.

67,030
Total Population
160
Population Density (mi²)
22
Population Rank (State)
162 0.24%
Annual Population Growth

Williamson County Population

Williamson County Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of Williamson County includes 89.24% White, 3.49% Black or African American, and smaller percentages for Asian, Native American, other race and multiracial populations.

Population by Race

Race
Population
Percentage (of total)
White59,70289.24%
Two or more races3,2884.91%
Black or African American2,3333.49%
Asian1,0431.56%
Native American3100.46%
Other race2260.34%

Williamson County Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Williamson County's average per capita income is $45,965. Household income levels show a median of $65,521. The poverty rate stands at 14.28%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$102,560$119,532
Families$85,336$103,135
Households$65,521$85,557
Non Families$36,994$52,193

$45,965

Average Income

$65,521

Median Household Income

14.28%

Poverty Rate