St. Clair County's estimated 2026 population is 160,668 with a growth rate of 0.11% in the past year according to the most recent United States census data. St. Clair County is the 13th largest county in Michigan. The 2010 population was 162,688 and has seen a growth of -1.24% since that time.
Data after 2023 is projected based on recent change
Overall: 44.5 years
Female: 45.5 years
Male: 43.4 years
There are 127,743 adults, (32,649 of whom are seniors) in St. Clair County.
Female: 79,977 (49.9%)
Male: 80,244 (50.1%)
The racial composition of St. Clair County includes 91.21% White, and smaller percentages for Black or African American, other race, Asian, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
Race | Population | Percentage (of total) |
|---|---|---|
| White | 146,136 | 91.21% |
| Two or more races | 7,697 | 4.8% |
| Black or African American | 3,491 | 2.18% |
| Other race | 1,746 | 1.09% |
| Asian | 865 | 0.54% |
| Native American | 271 | 0.17% |
| Native Hawaiian or Pacific Islander | 15 | 0.01% |
St. Clair County's average per capita income is $47,476. Household income levels show a median of $71,270. The poverty rate stands at 11.28%.
Name | Median | Mean |
|---|---|---|
| Married Families | $100,098 | $118,635 |
| Families | $87,930 | $105,549 |
| Households | $71,270 | $90,649 |
| Non Families | $41,280 | $56,878 |
Average Income
Median Household Income
Poverty Rate