Greene County area

Population and density of Greene County

The Census Bureau estimates that 174,322 people lived in Greene County on July 1, 2025. That ranks #405 of 3,222 county equivalents nationally and #18 of 88 in Ohio. Since the April 1, 2020 estimates base of 167,972, the population has grown by 6,350 (+3.8%), compared with +0.9% for Ohio as a whole.

With 413.6 square miles of land, that is 421 people per square mile (163 per km²), placing Greene County #395 nationally for density and #16 in Ohio. The median county equivalent has 47 people per square mile; the Ohio median is 120. Put another way, there are about 1.5 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Greene County

13 incorporated places lie at least partly in Greene County. Together they are home to 129,917 people (74.5%); the other 44,405 (25.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Beavercreek city, with 48,134 residents in the county. The county seat, Xenia city, has 26,425 residents. By land, Dayton city is the largest at 55.8 mi² across all its counties. Among places with at least 1,000 residents in 2020, Cedarville village grew fastest since then (+8.7%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Greene County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Greene County is a central county of the Dayton-Kettering-Beavercreek, OH Metropolitan Statistical Area. Its 3 county equivalents have 826,554 residents on 1,281.6 square miles of land; Greene County accounts for 32.3% of the land and 21.1% of the residents. By combined land it ranks #243 of 393 metropolitan areas, and #77 by population. It belongs to the Dayton-Springfield-Kettering, OH Combined Statistical Area.

ZIP codes

25 ZIP Code Tabulation Areas have land in Greene County; 17 of them have most of their land inside the county, and the others mainly cover neighboring areas.

43153450684516945301453054530745314453164532445335453684537045384453854538745424454304543145432454334543445435454404545845459

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Greene County

Greene County shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is Madison County (466.7 mi²) and the smallest is Clark County (395.9 mi²). Together with its neighbors, Greene County forms a block of 2,954.1 mi² of land, of which it holds 14%.

How big is Greene County compared with U.S. states?

Greene County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.5 times as much. Ohio’s county land could hold about 99 areas the size of Greene County.

Another way to picture it: the same land area would fill a square about 20.3 miles (32.7 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Greene County?

Greene County has more land than 778 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Greene County at #2,509 nationally by total area, 65 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 0.6%, compared with a national county-equivalent median of 1.2% — 0.5 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Greene County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.