| County: | Montgomery County |
| State: | Ohio |
| Flag: | Flag of Montgomery County, Ohio.png |
| Seal: | Seal of Montgomery County Ohio.svg |
| Founded Year: | 1803[1] |
| Founded Date: | May 1 |
| Seat Wl: | Dayton |
| Largest City Wl: | Dayton |
| Area Total Sq Mi: | 464 |
| Area Land Sq Mi: | 462 |
| Area Water Sq Mi: | 2.8 |
| Area Percentage: | 0.6% |
| Census Yr: | 2020 |
| Pop: | 537309 |
| Pop Est As Of: | 2021 |
| Population Est: | 535840 |
| Density Sq Mi: | auto |
| Time Zone: | Eastern |
| Web: | www.mcohio.org |
| Ex Image: | New Montgomery County Courthouse, Dayton.jpg |
| Ex Image Cap: | Current Montgomery County Courthouse |
| District: | 10th |
Montgomery County is in the southwestern part of the U.S. state of Ohio. At the 2020 census, the population was 537,309,[2] making it the fifth-most populous county in Ohio. The county seat is Dayton.[3] The county was named in honor of Richard Montgomery, an American Revolutionary War general, who was killed in 1775 while attempting to capture Quebec City, Canada.[4] Montgomery County is part of the Dayton, Ohio, Metropolitan Statistical Area.
The county has a total area of, of which is land and (0.6%) is water.[5]
As of the census of 2000, there were 559,062 people, 229,229 households, and 146,935 families living in the county. The population density was 1211/mi2. There were 248,443 housing units at an average density of 538/mi2. The racial makeup of the county was 76.57% White, 19.86% Black or African American, 0.23% Native American, 1.31% Asian, 0.04% Pacific Islander, 0.49% from other races, and 1.51% from two or more races. 1.27% of the population were Hispanic or Latino of any race.
There were 229,229 households, out of which 29.60% had children under the age of 18 living with them, 46.30% were married couples living together, 13.80% had a female householder with no husband present, and 35.90% were non-families. 30.40% of all households were made up of individuals, and 10.10% had someone living alone who was 65 years of age or older. The average household size was 2.37, and the average family size was 2.96.
In the county, the population was spread out, with 24.70% under the age of 18, 9.70% from 18 to 24, 29.00% from 25 to 44, 22.90% from 45 to 64, and 13.70% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 92.30 males. For every 100 females age 18 and over, there were 88.60 males.
The median income for a household in the county was $40,156, and the median income for a family was $50,071. Males had a median income of $38,710 versus $27,297 for females. The per capita income for the county was $21,743. About 8.30% of families and 11.30% of the population were below the poverty line, including 15.60% of those under age 18 and 8.20% of those age 65 or over.
As of the 2010 census, there were 535,153 people, 223,943 households, and 138,060 families living in the county.[6] The population density was . There were 254,775 housing units at an average density of .[7] The racial makeup of the county was 73.9% white, 20.9% black or African American, 1.7% Asian, 0.2% American Indian, 0.8% from other races, and 2.4% from two or more races. Those of Hispanic or Latino origin made up 2.3% of the population.[6] In terms of ancestry, 24.9% were German, 12.8% were Irish, 9.7% were American, and 8.8% were English.[8]
Of the 223,943 households, 29.7% had children under the age of 18 living with them, 41.6% were married couples living together, 15.3% had a female householder with no husband present, 38.4% were non-families, and 32.2% of all households were made up of individuals. The average household size was 2.33, and the average family size was 2.94. The median age was 39.2 years.[6]
The median income for a household in the county was $43,965, and the median income for a family was $56,559. Males had a median income of $45,680 versus $34,991 for females. The per capita income for the county was $24,828. About 11.7% of families and 15.7% of the population were below the poverty line, including 22.7% of those under age 18 and 8.7% of those aged 65 or over.[9]
See also: Ohio county government and Montgomery County, Ohio elections.
Montgomery County has been a slightly Democratic-leaning swing county since the Civil War. After voting consistently Democratic in presidential elections from 1992 to 2012, Republican Donald Trump narrowly defeated Democrat Hillary Clinton in the county in 2016. The last Democrat to win the county by double digits was Lyndon B. Johnson in 1964, while the last Republican to do so was George H. W. Bush in 1988.
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The following public school districts are located partially or entirely in Montgomery County:[10]
There is also a public independent (not a part of any school district) STEM school:
The following private high schools are located in Montgomery County: