Belmont County area

Population and density of Belmont County

The Census Bureau estimates that 64,434 people lived in Belmont County on July 1, 2025. That ranks #861 of 3,222 county equivalents nationally and #38 of 88 in Ohio. Since the April 1, 2020 estimates base of 66,495, the population has declined by 2,061 (−3.1%), compared with +0.9% for Ohio as a whole.

With 532.2 square miles of land, that is 121 people per square mile (47 per km²), placing Belmont County #871 nationally for density and #44 in Ohio. The median county equivalent has 47 people per square mile; the Ohio median is 120. Put another way, there are about 5.3 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 Belmont County

16 incorporated places lie at least partly in Belmont County. Together they are home to 28,761 people (44.6%); the other 35,673 (55.4%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Martins Ferry city, with 6,048 residents in the county. The county seat, St. Clairsville city, has 4,926 residents. By land, St. Clairsville city is the largest at 2.422 mi².

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

Metropolitan area

Belmont County is a central county of the Wheeling, WV-OH Metropolitan Statistical Area. Its 3 county equivalents have 134,089 residents on 943.6 square miles of land; Belmont County accounts for 56.4% of the land and 48.1% of the residents. By combined land it ranks #287 of 393 metropolitan areas, and #313 by population.

ZIP codes

29 ZIP Code Tabulation Areas have land in Belmont County; 23 of them have most of their land inside the county, and the others mainly cover neighboring areas.

4371343716437184371943747437594390143902439054390643909439124391743928439334393443935439404394243943439474395043951439674397143972439774398343985

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 Belmont County

Belmont County shares a land border with 7 county equivalents, including 2 in West Virginia. It has more land than every one of them. The largest neighbor is Guernsey County (522.2 mi²) and the smallest is Ohio County (106 mi²). Together with its neighbors, Belmont County forms a block of 3,129.9 mi² of land, of which it holds 17%.

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

Belmont 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 77 areas the size of Belmont County.

Another way to picture it: the same land area would fill a square about 23.1 miles (37.1 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 Belmont County?

Belmont County has more land than 1,259 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 Belmont County at #2,035 nationally by total area, 72 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 1.7%, compared with a national county-equivalent median of 1.2% — 0.5 percentage points higher. 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 Belmont 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.