[4] When organized, the county's eastern border was with the state of 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.

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.

[5] 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.

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.

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.

As of the 2010 United States census, there were 14,642 people, 6,065 households, and 4,183 families living in the county.

In 2016, it took a sharp turn to the right, voting for Donald Trump by a large margin.

However, in 2018 it voted for Republican Mike DeWine over Democrat Richard Cordray.

Current Commissioners are: Mick Schumacher (R), Bill Bolon (R), and Diane Burkhart (R).