Mason County's 2026 population is estimated at 12,453, reflecting a -0.36% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Mason County is the 82nd largest county in Illinois. The 2010 population was 14,651 and has grown -15% since 2010.
Data after 2023 is projected based on recent change
Overall: 45.4 years
Female: 45.9 years
Male: 44.6 years
There are 10,098 adults, (2,939 of whom are seniors) in Mason County.
Female: 6,414 (50.3%)
Male: 6,331 (49.7%)
The racial composition of Mason County includes 94.61% White, and smaller percentages for Black or African American, other race, Native American, Asian and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 12,058 | 94.61% |
| Two or more races | 418 | 3.28% |
| Black or African American | 96 | 0.75% |
| Other race | 67 | 0.53% |
| Native American | 54 | 0.42% |
| Asian | 52 | 0.41% |
Mason County 's average per capita income is $43,872. Household income levels show a median of $62,845. The poverty rate stands at 14.83%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $94,653 | - |
| Families | $79,716 | $91,925 |
| Households | $62,845 | $78,083 |
| Non Families | $37,473 | $52,944 |
Average Income
Median Household Income
Poverty Rate
