Williamson County's estimated 2026 population is 67,718 with a growth rate of 0.49% 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 1.92% since that time.
Data after 2023 is projected based on recent change
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.
White (89.24%)
Two or more races (4.91%)
Black or African American (3.49%)
Asian (1.56%)
Native American (0.46%)
Other race (0.34%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 59,702 | 89.24% |
| Two or more races | 3,288 | 4.91% |
| Black or African American | 2,333 | 3.49% |
| Asian | 1,043 | 1.56% |
| Native American | 310 | 0.46% |
| Other race | 226 | 0.34% |
Married
Widowed
Divorced
Separated
Never Married
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%.
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 |
Average Income
Median Household Income
Poverty Rate
