For every 100 females age 18 and over, there were 88.60 males. The per capita income for the county was $24,828.

In addition, the U.S. resident population excludes U.S. Armed Forces overseas and civilian U.S. citizens whose usual place of residence is outside the United States. There were 254,775 housing units at an average density of 552.0 per square mile (213.1/km2).

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. Males had a median income of $45,680 versus $34,991 for females. 2 Rates are per 100,000 and age-adjusted to the 2000 U.S. Standard Population. For the United States, the resident population includes all persons who usually reside in the 50 states and the District of Columbia, but excludes residents of the Commonwealth of Puerto Rico and the Island areas under U.S. sovereignty or jurisdiction (principally American Samoa, Guam, United States Virgin Islands, and the Commonwealth of the Northern Mariana Islands). The average household size was 2.37, and the average family size was 2.96. Value for Ohio (Number): 11,689,100 Data item: Population, 2019 estimate Sources: U.S. … The median age was 36 years. [12], The median income for a household in the county was $43,965, and the median income for a family was $56,559.

[4] The county was named in honor of Richard Montgomery, an American Revolutionary War general killed in 1775 while attempting to capture Quebec City, Canada.[5]. Population percent change - The difference between the population of an area at the beginning and end of a time period, expressed as a percentage of the beginning population.

Resident Population - All persons who are "usually resident" in a specified geographic area. The population density was 1,211 people per square mile (468/km2). The following public school districts are located partially or entirely in Montgomery County: The following private high schools are located in Montgomery County: https://web.archive.org/web/20160715023447/http://www.ohiotownships.org/township-websites, Coordinates: 39°45′N 84°17′W / 39.75°N 84.29°W / 39.75; -84.29, Places adjacent to Montgomery County, Ohio, ‡This populated place also has portions in an adjacent county or counties, Dayton Aviation Heritage National Historical Park, Election Results, Montgomery County, Ohio, National Register of Historic Places listings in Montgomery County, Ohio, "Ohio County Profiles: Montgomery County", "Ohio 2010 Census Population For Counties", "Population of Counties by Decennial Census: 1900 to 1990", "Census 2000 PHC-T-4.

Population of male led with no wife present: Population female led with no husband present: Population of homes with one or more people under 18 years: Households with no people under 18 years: Population of homes with one or more people 60 years and over: Population of homes with no people 60 years and over: Home does not have three or more generations: Population of male led and male partner homes: Population of male led and female partner households: Population of female led and female partner households: Population of female led and male partner households: Population of male led and female partner homes: Population of female led and female partner homes: Population of female led and male partner homes: No unmarried partner of home lead present: Population of male lead with no wife present, family homes: Population of female lead with no husband present, family homes. As of the census of 2000, there were 559,062 people, 229,229 households, and 146,935 families living in the county. For every 100 females, there were 92.30 males. The per capita income for the county was $21,743. The county seat is Dayton.