How many people live in Madison County, OH?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 45,500 people living in Madison County, OH. That makes Madison County the 53rd-most populous county in Ohio. It is home to 0.38% of people living in the state.
45.5K
population of Madison County, OH (2024)
0.38%
County share of the Ohio population (2024)
About 45,500 people lived in Madison County, OH in 2024.
Population estimates, 2000–2024
What are Madison County, OH’s age demographics?
About 7,900 Madison County, OH residents are aged 65 and older in 2024. That represents 17.4% of its population. For comparison, the age group represents 19.1% of Ohio’s population and 18% in the US overall.
Another 8,900 Madison County residents, or 19.5% of the population, were children under 18. For comparison, the age group represents 21.7% of Ohio’s population and 21.6% in the US overall.
A higher share of Madison County, OH's population is aged 45–64 than the US as a whole.
Population estimates by age group, (2024)
What are Madison County, OH’s racial and ethnic demographics?
Non-Hispanic white residents make up 86.2% of the Madison County, OH population, higher than the national share of 57.5%.
In contrast, Madison County’s Hispanic population accounts for 3.5%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 6.3% 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.
Madison County, OH has a higher share of a non-Hispanic white population than Ohio as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Madison County, OH is London with about 10,700 residents in 2024.
Cities and towns in Madison County, OH ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | London | 10,743 |
| 2. | Union | 5,618 |
| 3. | West Jefferson (pt.) | 4,943 |
| 4. | Plain City (pt.) | 3,620 |
| 5. | Somerford | 3,107 |
| 6. | Canaan | 2,724 |
| 7. | Mount Sterling | 2,070 |
| 8. | Monroe | 1,695 |
| 9. | Fairfield | 1,462 |
| 10. | Paint | 571 |
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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.
