County outline
Where Richland County is located
Area breakdown
Land accounts for 99% of Richland County’s measured area and water for 1%. Its combined area converts to 1,295.2 square kilometers or approximately 320,049 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 495.227 | 1,282.632 | 316,945.3 |
| Water | 4.849 | 12.559 | 3,103.4 |
| Total | 500.076 | 1,295.191 | 320,048.6 |
How Richland County compares
By original Census land area, Richland County ranks #26 of 88 in Ohio and #2101 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.136 times the Ohio county-equivalent median of 436 square miles. It accounts for 1.2% of the combined county land area in the state.
See the complete Ohio ranking · What counts as a county equivalent?
Population and density of Richland County
The Census Bureau estimates that 124,893 people lived in Richland County on July 1, 2025. That ranks #527 of 3,222 county equivalents nationally and #23 of 88 in Ohio. Since the April 1, 2020 estimates base of 124,926, the population has declined by 33 (−0%), compared with +0.9% for Ohio as a whole.
With 495.2 square miles of land, that is 252 people per square mile (97 per km²), placing Richland County #570 nationally for density and #24 in Ohio. The median county equivalent has 47 people per square mile; the Ohio median is 120. Put another way, there are about 2.5 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 124,969 | 125,297 | 125,076 | 124,863 | 124,957 | 124,893 |
| Change | — | +328 | −221 | −213 | +94 | −64 |
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 Richland County
11 incorporated places lie at least partly in Richland County. Together they are home to 73,220 people (58.6%); the other 51,673 (41.4%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Mansfield city, with 47,381 residents in the county. Among places with at least 1,000 residents in 2020, Bellville village grew fastest since then (+2.7%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Mansfield cityCounty seat | 47,381 | −0.2% | 30.9 |
| Shelby city | 9,231 | −0.5% | 6.328 |
| Ontario city | 6,692 | +0.1% | 11.1 |
| Lexington village | 4,848 | +0% | 4.131 |
| Bellville village | 2,013 | +2.7% | 2.873 |
| Butler village | 929 | −0.4% | 1.29 |
| Plymouth villageAlso in 1 other county | 906 | +0.1% | 2.499 |
| Shiloh village | 615 | −0.5% | 0.916 |
| Lucas village | 586 | −0.5% | 0.677 |
| Crestline villageAlso in 1 other county | 19 | 0% | 3.394 |
| Galion cityAlso in 2 other counties | 0 | — | 7.426 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Richland County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Richland County is a central county of the Mansfield, OH Metropolitan Statistical Area. Richland County is the area’s only county equivalent, so the metro area has the same 495.2 square miles of land. By combined land it ranks #362 of 393 metropolitan areas, and #331 by population. It belongs to the Mansfield-Ashland-Bucyrus, OH Combined Statistical Area.
ZIP codes
19 ZIP Code Tabulation Areas have land in Richland County; 12 of them have most of their land inside the county, and the others mainly cover neighboring areas.
43019448054481344822448274483344837448434486444865448754487844901449024490344904449054490644907
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 Richland County
Richland County shares a land border with 5 county equivalents. It has more land than 4 of them. The largest neighbor is Knox County (525.5 mi²) and the smallest is Crawford County (401.8 mi²). Together with its neighbors, Richland County forms a block of 2,743.9 mi² of land, of which it holds 18%.
| Bordering county equivalent | Land mi² | Size vs. Richland | Compare |
|---|---|---|---|
| Knox County | 525.5 | 1.1× larger | Compare |
| Huron County | 492.2 | about the same | Compare |
| Ashland County | 423 | 1.2× smaller | Compare |
| Morrow County | 406.1 | 1.2× smaller | Compare |
| Crawford County | 401.8 | 1.2× smaller | Compare |
How big is Richland County compared with U.S. states?
Richland County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.1 times as much. Ohio’s county land could hold about 83 areas the size of Richland County.
Another way to picture it: the same land area would fill a square about 22.3 miles (35.8 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 Richland County?
Richland County has more land than 1,121 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 Richland County at #2,182 nationally by total area, 81 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 1%, compared with a national county-equivalent median of 1.2% — 0.2 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 Richland County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2100 | Fulton County, New York | 495.5 | Compare |
| #2101 | Richland County, Ohio | 495.2 | This county |
| #2102 | Louisa County, Virginia | 495.1 | 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 40.774159, -82.542768. 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: 1,282,631,578 m²; AWATER: 12,560,134 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 Richland County?
Richland County, Ohio has 495.2 square miles (1,282.6 km²) of land and 4.849 square miles of water, for a total area of 500.1 square miles. It ranks #2101 of 3,222 U.S. county equivalents by land area.
Is Richland County the largest county in Ohio?
No. Richland County ranks #26 of 88 in Ohio by land area. The largest is Ashtabula County, with 702.4 square miles of land.
What counties border Richland County?
Richland County shares a land border with Ashland County, Crawford County, Morrow County, Huron County, and Knox County.
What is the population of Richland County?
The Census Bureau estimates Richland County had 124,893 residents on July 1, 2025, ranking #527 of 3,222 county equivalents. That is 252 people per square mile of land.
What is the county seat of Richland County?
The county seat of Richland County is Mansfield.
What cities and towns are in Richland County?
Richland County has 11 incorporated places. The most populous five are Mansfield city, Shelby city, Ontario city, Lexington village, and Bellville village; 51,673 residents live outside any incorporated place.
Is Richland County part of a metropolitan area?
Yes. It is a central county of the Mansfield, OH Metropolitan Statistical Area.
How many ZIP codes are in Richland County?
19 ZIP Code Tabulation Areas have land in Richland County, and 12 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Richland County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.1 times as much land.
How many acres of land are in Richland County?
The land measurement converts to approximately 316,945 acres. Including water, total area is approximately 320,049 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.