Monroe County is a county located on the eastern border of the U.S. state of Ohio, across the Ohio River from West Virginia. As of 2023, the population was 13,153, making it the second-least populous county in Ohio. Its county seat is Woodsfield. The county was created in 1813 and later organized in 1815.

Monroe County was formed on January 28, 1813, from portions of Belmont, Guernsey and Washington counties. It was named after James Monroe, the U.S. Secretary of State when the county was formed, and later fifth President of the United States. When organized, the county's eastern border was with the state of Virginia. This portion of the state seceded from Virginia during the American Civil War, being admitted to the Union as the state of West Virginia. The largely rural county reached its peak of population in the 19th century, before urbanization drew people into and near cities for work and other opportunities. It is still a center of Amish population and farms.

In 1891, West Virginia's Sistersville Field was discovered to extend into Monroe County. By 1901, 300 wells near Woodsfield, Ohio, were producing 55,000 barrels of oil a month.

On or about December 20, 2011, ExxonMobil, a New Jersey petroleum company, via its subsidiary XTO Energy, acquired 20,056 acres of Monroe County Utica Shale gas leases from Beck Energy.

According to the United States Census Bureau, the county has a total area of 457 square miles (1,180 km), of which 456 square miles (1,180 km) is land and 1.7 square miles (4.4 km) (0.4%) is water. It is bordered by the Ohio River to the east. The terrain is hilly in this area, with waterways cutting through some hills of the Appalachian Plateau, which extends from Lake Erie to the Ohio River, which flows southwest to the south of this county.

• Belmont County (north)
• Marshall County, West Virginia (northeast)
• Wetzel County, West Virginia (east)
• Tyler County, West Virginia (southeast)
• Washington County (south)
• Noble County (west)

• Wayne National Forest (part)

Historical population

Census	Pop.	Note	%±
1820	4,645		—
1830	8,768		88.8%
1840	18,521		111.2%
1850	28,351		53.1%
1860	25,741		−9.2%
1870	25,779		0.1%
1880	26,496		2.8%
1890	25,175		−5.0%
1900	27,031		7.4%
1910	24,244		−10.3%
1920	20,660		−14.8%
1930	18,426		−10.8%
1940	18,641		1.2%
1950	15,362		−17.6%
1960	15,268		−0.6%
1970	15,739		3.1%
1980	17,382		10.4%
1990	15,497		−10.8%
2000	15,180		−2.0%
2010	14,642		−3.5%
2020	13,385		−8.6%
2021 (est.)	13,329		−0.4%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2020

As of the census of 2000, there were 15,180 people, 6,021 households, and 4,413 families living in the county. The population density was 33 people per square mile (13 people/km). There were 7,212 housing units at an average density of 16 units per square mile (6.2/km). The racial makeup of the county was 98.72% White, 0.26% Black or African American, 0.15% Native American, 0.07% Asian, 0.01% Pacific Islander, 0.11% from other races, and 0.67% from two or more races. 0.41% of the population were Hispanic or Latino of any race.

There were 6,021 households, out of which 29.50% had children under the age of 18 living with them, 61.70% were married couples living together, 8.10% had a female householder with no husband present, and 26.70% were non-families. 24.00% of all households were made up of individuals, and 11.50% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 2.96.

In the county, the population was spread out, with 23.60% under the age of 18, 7.10% from 18 to 24, 25.90% from 25 to 44, 27.20% from 45 to 64, and 16.30% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 97.50 males. For every 100 females age 18 and over, there were 96.10 males.

The median income for a household in the county was $30,467, and the median income for a family was $36,297. Males had a median income of $33,308 versus $19,628 for females. The per capita income for the county was $15,096. About 11.00% of families and 13.90% of the population were below the poverty line, including 18.30% of those under age 18 and 11.40% of those age 65 or over.

As of the 2010 United States census, there were 14,642 people, 6,065 households, and 4,183 families living in the county. The population density was 32.1 inhabitants per square mile (12.4/km). There were 7,567 housing units at an average density of 16.6 units per square mile (6.4 units/km). The racial makeup of the county was 98.1% white, 0.4% black or African American, 0.1% Asian, 0.1% American Indian, 0.1% from other races, and 1.2% from two or more races. Those of Hispanic or Latino origin made up 0.4% of the population. In terms of ancestry, 34.8% were German, 14.5% were Irish, 10.6% were English, and 9.6% were American.

Of the 6,065 households, 27.3% had children under the age of 18 living with them, 56.0% were married couples living together, 8.6% had a female householder with no husband present, 31.0% were non-families, and 27.3% of all households were made up of individuals. The average household size was 2.39 and the average family size was 2.87. The median age was 44.7 years.

The median income for a household in the county was $37,030 and the median income for a family was $43,261. Males had a median income of $39,261 versus $24,922 for females. The per capita income for the county was $18,738. About 12.3% of families and 17.3% of the population were below the poverty line, including 26.7% of those under age 18 and 12.3% of those age 65 or over.

As was typical for Appalachian counties, Monroe County voted Democratic in most elections – all but 7 times from 1856 until 2008. In 2012, it voted Republican for the first time since 1972. In 2016, it took a sharp turn to the right, voting for Donald Trump by a large margin. In the 2014 gubernatorial election, Monroe was one of two counties to vote for Democrat Ed FitzGerald over Republican John Kasich (along with Athens County). However, in 2018 it voted for Republican Mike DeWine over Democrat Richard Cordray.

United States presidential election results for Monroe County, Ohio

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	5,396	79.18%	1,336	19.60%	83	1.22%
2020	5,463	76.31%	1,605	22.42%	91	1.27%
2016	4,868	71.03%	1,662	24.25%	323	4.71%
2012	3,548	52.31%	3,035	44.75%	199	2.93%
2008	3,066	43.91%	3,705	53.07%	211	3.02%
2004	3,424	44.30%	4,243	54.90%	62	0.80%
2000	3,145	44.20%	3,605	50.67%	365	5.13%
1996	1,856	26.64%	3,914	56.18%	1,197	17.18%
1992	1,823	24.02%	4,235	55.79%	1,533	20.19%
1988	2,557	37.20%	4,269	62.10%	48	0.70%
1984	3,302	47.32%	3,611	51.75%	65	0.93%
1980	2,870	45.03%	3,166	49.68%	337	5.29%
1976	2,728	38.25%	4,296	60.24%	108	1.51%
1972	3,721	59.14%	2,483	39.46%	88	1.40%
1968	2,686	42.27%	3,105	48.87%	563	8.86%
1964	1,944	28.93%	4,776	71.07%	0	0.00%
1960	4,106	56.63%	3,144	43.37%	0	0.00%
1956	3,738	59.18%	2,578	40.82%	0	0.00%
1952	3,493	52.09%	3,213	47.91%	0	0.00%
1948	2,574	39.88%	3,873	60.01%	7	0.11%
1944	3,617	50.30%	3,574	49.70%	0	0.00%
1940	4,534	52.28%	4,138	47.72%	0	0.00%
1936	3,211	36.87%	5,368	61.64%	130	1.49%
1932	2,767	33.97%	5,263	64.61%	116	1.42%
1928	4,287	60.73%	2,729	38.66%	43	0.61%
1924	2,674	40.58%	3,742	56.79%	173	2.63%
1920	2,825	41.94%	3,861	57.32%	50	0.74%
1916	1,504	30.61%	3,322	67.62%	87	1.77%
1912	1,055	21.79%	3,199	66.08%	587	12.13%
1908	1,974	32.74%	3,961	65.69%	95	1.58%
1904	2,222	40.17%	3,169	57.30%	140	2.53%
1900	2,103	33.33%	4,143	65.66%	64	1.01%
1896	2,001	32.07%	4,180	67.00%	58	0.93%
1892	1,630	29.08%	3,838	68.47%	137	2.44%
1888	1,621	29.04%	3,886	69.63%	74	1.33%
1884	1,645	28.99%	4,010	70.66%	20	0.35%
1880	1,600	29.30%	3,751	68.70%	109	2.00%
1876	1,462	27.71%	3,805	72.11%	10	0.19%
1872	1,307	30.74%	2,878	67.69%	67	1.58%
1868	1,443	29.81%	3,397	70.19%	0	0.00%
1864	1,440	31.03%	3,201	68.97%	0	0.00%
1860	1,335	28.57%	3,147	67.36%	190	4.07%
1856	1,016	23.96%	2,812	66.31%	413	9.74%

Monroe County has three County Commissioners who oversee the various County departments, similar to 85 of the other 88 Ohio counties. Current Commissioners are: Mick Schumacher (R), Bill Bolon (R), and Diane Burkhart (R).

Monroe County is served by the Monroe County District Library from its administrative offices in Woodsfield, Ohio; it also offers a bookmobile service.

In 2005, the library loaned more than 141,000 items to its 6,000 cardholders. Total holding are over 64,000 volumes with over 140 periodical subscriptions. This library is a member of the SOLO Regional Library System.

Monroe County contains the following schools through the Switzerland of Ohio Local School District:

• Elementary Schools
  • Beallsville Elementary School in Beallsville, Ohio
  • River Elementary School in Hannibal, Ohio
  • Skyvue Elementary School in Graysville, Ohio
  • Woodsfield Elementary School in Woodsfield, Ohio
  • St. Sylvester Central in Woodsfield, Ohio
• High Schools
  • Monroe Central High School in Woodsfield, Ohio
  • River High School in Hannibal, Ohio
  • Beallsville High School in Beallsville, Ohio
• Career Center
  • Swiss Hills Career Center in Woodsfield, Ohio

• Hannibal
• Sardis

• Cameron
• Duffy
• Fly
• Laings
• Malaga
• Rinard Mills
• Sardis
• Sycamore Valley

• Quarry

• Philip Allen, member of the Wisconsin State Assembly
• William C. Chynoweth, member of the Illinois House of Representatives
• Sam V. Stewart, Montana Supreme Court Justice and the sixth Governor of Montana

• National Register of Historic Places listings in Monroe County, Ohio
• Petroleum industry in Ohio

• Thomas William Lewis, History of Southeastern Ohio and the Muskingum Valley, 1788-1928. In Three Volumes. Chicago: S.J. Clarke Publishing Co., 1928.

• Monroe County Economic Development and Tourism
• Monroe County Public Library website

39°44′N 81°05′W / 39.73°N 81.08°W / 39.73; -81.08