County outline
Where Highland County is located
Area breakdown
Land accounts for 99.2% of Highland County’s measured area and water for 0.8%. Its combined area converts to 1,444.7 square kilometers or approximately 356,988 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 553.084 | 1,432.481 | 353,973.8 |
| Water | 4.709 | 12.196 | 3,013.8 |
| Total | 557.793 | 1,444.677 | 356,987.5 |
How Highland County compares
By original Census land area, Highland County ranks #15 of 88 in Ohio and #1888 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.269 times the Ohio county-equivalent median of 436 square miles. It accounts for 1.4% of the combined county land area in the state.
See the complete Ohio ranking · What counts as a county equivalent?
Population and density of Highland County
The Census Bureau estimates that 43,823 people lived in Highland County on July 1, 2025. That ranks #1,142 of 3,222 county equivalents nationally and #56 of 88 in Ohio. Since the April 1, 2020 estimates base of 43,317, the population has grown by 506 (+1.2%), compared with +0.9% for Ohio as a whole.
With 553.1 square miles of land, that is 79 people per square mile (31 per km²), placing Highland County #1,166 nationally for density and #67 in Ohio. The median county equivalent has 47 people per square mile; the Ohio median is 120. Put another way, there are about 8.1 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 43,363 | 43,440 | 43,352 | 43,532 | 43,704 | 43,823 |
| Change | — | +77 | −88 | +180 | +172 | +119 |
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 Highland County
8 incorporated places lie at least partly in Highland County. Together they are home to 14,645 people (33.4%); the other 29,178 (66.6%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Hillsboro city, with 6,763 residents in the county. Among places with at least 1,000 residents in 2020, Hillsboro city grew fastest since then (+5.1%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Hillsboro cityCounty seat | 6,763 | +5.1% | 5.475 |
| Greenfield villageAlso in 1 other county | 4,329 | −0.3% | 2.082 |
| Lynchburg villageAlso in 1 other county | 1,537 | +1.9% | 0.923 |
| Leesburg village | 1,280 | +0.9% | 1.167 |
| Mowrystown village | 387 | +0.3% | 0.482 |
| Highland village | 229 | +0.4% | 0.17 |
| Sinking Spring village | 120 | 0% | 0.467 |
| Sardinia villageAlso in 1 other county | 0 | — | 1.754 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Highland County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Highland County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
15 ZIP Code Tabulation Areas have land in Highland County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
451184512345132451334513545142451544515545159451714517245612456604567945697
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 Highland County
Highland County shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is Ross County (689.2 mi²) and the smallest is Fayette County (406.4 mi²). Together with its neighbors, Highland County forms a block of 3,571 mi² of land, of which it holds 15.5%.
| Bordering county equivalent | Land mi² | Size vs. Highland | Compare |
|---|---|---|---|
| Ross County | 689.2 | 1.2× larger | Compare |
| Adams County | 583.9 | 1.1× larger | Compare |
| Brown County | 489.6 | 1.1× smaller | Compare |
| Pike County | 440.3 | 1.3× smaller | Compare |
| Clinton County | 408.7 | 1.4× smaller | Compare |
| Fayette County | 406.4 | 1.4× smaller | Compare |
How big is Highland County compared with U.S. states?
Highland County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.9 times as much. Ohio’s county land could hold about 74 areas the size of Highland County.
Another way to picture it: the same land area would fill a square about 23.5 miles (37.8 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 Highland County?
Highland County has more land than 1,334 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 Highland County at #1,979 nationally by total area, 91 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 0.8%, compared with a national county-equivalent median of 1.2% — 0.3 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 Highland County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1887 | Coahoma County, Mississippi | 553.1 | Compare |
| #1888 | Highland County, Ohio | 553.1 | This county |
| #1889 | Davidson County, North Carolina | 553 | Compare |
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.
Representative coordinates
The Census internal point is 39.184422, -83.601359. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,432,479,972 m²; AWATER: 12,194,983 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Highland County?
Highland County, Ohio has 553.1 square miles (1,432.5 km²) of land and 4.709 square miles of water, for a total area of 557.8 square miles. It ranks #1888 of 3,222 U.S. county equivalents by land area.
Is Highland County the largest county in Ohio?
No. Highland County ranks #15 of 88 in Ohio by land area. The largest is Ashtabula County, with 702.4 square miles of land.
What counties border Highland County?
Highland County shares a land border with Brown County, Clinton County, Adams County, Ross County, Fayette County, and Pike County.
What is the population of Highland County?
The Census Bureau estimates Highland County had 43,823 residents on July 1, 2025, ranking #1,142 of 3,222 county equivalents. That is 79 people per square mile of land.
What is the county seat of Highland County?
The county seat of Highland County is Hillsboro.
What cities and towns are in Highland County?
Highland County has 8 incorporated places. The most populous five are Hillsboro city, Greenfield village, Lynchburg village, Leesburg village, and Mowrystown village; 29,178 residents live outside any incorporated place.
Is Highland County part of a metropolitan area?
No. Highland County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Highland County?
15 ZIP Code Tabulation Areas have land in Highland County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Highland County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.9 times as much land.
How many acres of land are in Highland County?
The land measurement converts to approximately 353,974 acres. Including water, total area is approximately 356,988 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.