How many people live in Sanilac County, MI?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 40,300 people living in Sanilac County, MI. That makes Sanilac County the 41st-most populous county in Michigan. It is home to 0.4% of people living in the state.
40.3K
population of Sanilac County, MI (2024)
0.4%
County share of the Michigan population (2024)
About 40,300 people lived in Sanilac County, MI in 2024.
Population estimates, 2000–2024
What are Sanilac County, MI’s age demographics?
About 9,900 Sanilac County, MI residents are aged 65 and older in 2024. That represents 24.6% of its population. For comparison, the age group represents 19.6% of Michigan’s population and 18% in the US overall.
Another 8,200 Sanilac County residents, or 20.4% of the population, were children under 18. For comparison, the age group represents 20.8% of Michigan’s population and 21.6% in the US overall.
A higher share of Sanilac County, MI's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Sanilac County, MI’s racial and ethnic demographics?
Non-Hispanic white residents make up 92.8% of the Sanilac County, MI population, higher than the national share of 57.5%.
In contrast, Sanilac County’s Hispanic population accounts for 4.4%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 0.63% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Sanilac County, MI has a higher share of a non-Hispanic white population than Michigan as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Sanilac County, MI is Worth with about 3,400 residents in 2024.
Cities and towns in Sanilac County, MI ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Worth | 3,445 |
| 2. | Sandusky | 2,679 |
| 3. | Croswell | 2,289 |
| 4. | Marlette | 1,843 |
| 5. | Marlette | 1,669 |
| 6. | Brown City (pt.) | 1,288 |
| 7. | Watertown | 1,246 |
| 8. | Maple Valley | 1,167 |
| 9. | Buel | 1,164 |
| 10. | Moore | 1,096 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
