How many people live in Washtenaw County, MI?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 373,900 people living in Washtenaw County, MI. That makes Washtenaw County the sixth-most populous county in Michigan. It is home to 3.7% of people living in the state.
374K
population of Washtenaw County, MI (2024)
3.7%
County share of the Michigan population (2024)
About 373,900 people lived in Washtenaw County, MI in 2024.
Population estimates, 2000–2024
What are Washtenaw County, MI’s age demographics?
About 62,500 Washtenaw County residents are aged 65 and older in 2024. That represents 16.7% of its population. For comparison, the age group represents 19.6% of Michigan’s population and 18% in the US overall.
Another 66,700 Washtenaw County residents, or 17.8% 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 Washtenaw County, MI's population is aged 18–24 than the US as a whole.
Population estimates by age group, (2024)
What are Washtenaw County, MI’s racial and ethnic demographics?
Non-Hispanic white residents make up 67.6% of the Washtenaw County population, higher than the national share of 57.5%. Washtenaw County also has a larger share of people identifying as non-Hispanic Asian (10.8%) than the US overall (6.5%).
In contrast, Washtenaw County’s Hispanic population accounts for 6.1%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 11.7% 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.
Washtenaw County, MI has a higher share of a non-Hispanic Asian population than Michigan as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Washtenaw County, MI is Ann Arbor with about 122,900 residents in 2024.
Cities and towns in Washtenaw County, MI ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Ann Arbor | 122,925 |
| 2. | Ypsilanti | 54,760 |
| 3. | Pittsfield | 40,697 |
| 4. | Ypsilanti | 20,150 |
| 5. | Scio | 18,522 |
| 6. | Superior | 14,992 |
| 7. | York | 9,229 |
| 8. | Saline | 9,101 |
| 9. | Northfield | 8,936 |
| 10. | Augusta | 7,399 |
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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.
