2020 census
As of the 2020 census, the county had a population of 35,954. The median age was 43.7 years, 18.6% of residents were under the age of 18, and 20.2% of residents were 65 years of age or older. For every 100 females there were 109.3 males, and for every 100 females age 18 and over there were 109.6 males age 18 and over. [19]
Racial and ethnic composition is detailed in the table below. [20]
24.3% of residents lived in urban areas, while 75.7% lived in rural areas. [21]
There were 14,058 households in the county, of which 26.4% had children under the age of 18 living in them. Of all households, 48.0% were married-couple households, 19.6% were households with a male householder and no spouse or partner present, and 24.9% were households with a female householder and no spouse or partner present. About 29.4% of all households were made up of individuals and 13.7% had someone living alone who was 65 years of age or older. [19]
There were 16,138 housing units, of which 12.9% were vacant. Among occupied housing units, 73.4% were owner-occupied and 26.6% were renter-occupied. The homeowner vacancy rate was 1.9% and the rental vacancy rate was 9.1%. [19]
Greene County, Pennsylvania – Racial and ethnic composition
Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.| Race / Ethnicity (NH = Non-Hispanic) | Pop 2000 [22] | Pop 2010 [23] | Pop 2020 [24] | % 2000 | % 2010 | % 2020 |
|---|
| White alone (NH) | 38,365 | 36,409 | 32,898 | 94.32% | 94.11% | 91.50% |
| Black or African American alone (NH) | 1,579 | 1,272 | 1,062 | 3.88% | 3.28% | 2.95% |
| Native American or Alaska Native alone (NH) | 54 | 59 | 69 | 0.13% | 0.15% | 0.19% |
| Asian alone (NH) | 86 | 113 | 120 | 0.21% | 0.29% | 0.33% |
| Pacific Islander alone (NH) | 8 | 6 | 6 | 0.01% | 0.01% | 0.01% |
| Other race alone (NH) | 5 | 10 | 63 | 0.01% | 0.02% | 0.17% |
| Mixed race or Multiracial (NH) | 218 | 352 | 1,226 | 0.53% | 0.90% | 3.40% |
| Hispanic or Latino (any race) | 357 | 465 | 510 | 0.87% | 1.20% | 1.41% |
| Total | 40,672 | 38,686 | 35,954 | 100.00% | 100.00% | 100.00% |
2010 census
As of the census [25] of 2010, there were 38,686 people, 14,724 households, and 9,970 families residing in the county. The population density was 67 people per square mile (26 people/km2). There were 16,678 housing units at an average density of 29 units per square mile (11/km2). The racial makeup of the county was 94.6 percent White, 3.3 percent Black or African American, 0.2% Native American, 0.3 percent Asian, 0.0 percent Pacific Islander, 0.7 percent from other races, and 1.0% from two or more races. 1.2 percent of the population were Hispanic or Latino of any race.
There were 14,724 households, out of which 29.3 percent had children under the age of 18 living with them, 51.5 percent were married couples living together, 10.9 percent had a female householder with no husband present, and 32.3 percent were non-families. 27.0 percent of all households were made up of individuals, and 11.7 percent had someone living alone who was 65 years of age or older. The average household size was 2.42 and the average family size was 2.91.
The county population distribution by age was 19.9 percent under the age of 18, 9.9 percent from 18 to 24, 25.5 percent from 25 to 44, 29.3 percent from 45 to 64, and 15.3 percent who were 65 years of age or older. The median age was 41.1 years. For every 100 females there were 106.2 males. For every 100 females age 18 and over, there were 105.6 males.
United States
Pennsylvania 
