[7] Most of the county lies in the Glaciated Allegheny Plateau with rolling hills and valleys.

Although the relief is not sharp, some elevations in the county reach over 1400 feet above sea level.

25.7% of all households were made up of individuals, and 27.4% had someone living alone who was 65 years of age or older.

[16] As of the 2010 United States census, there were 60,921 people, 22,607 households, and 15,693 families living in the county.

People, who represent the county in various elected positions, at different levels of the government include: A large portion of Knox County's economy is based on agriculture, with gross cash receipts for crops and livestock at $110 million for 2011.

[7] Mount Vernon, the county seat, is home to major employers in the county, Siemens Energy Inc. (formerly Rolls-Royce Energy Systems, Inc. and Cooper Industries before that) and Ariel Corporation, both of which are manufacturers of components used in the natural gas industry.

Major employers in the county also include Kenyon College located in Gambier, Mount Vernon Nazarene University in Mount Vernon, and the Kokosing Construction Company near Fredericktown.

[22] Fossil fuel interests financed the local newspaper (Mount Vernon News), sent text messages to residents, funded an ostensibly grassroots opposition group and funded speakers who talked about the dangers of solar energy.

[22] Notable people, who lived or worked in Knox County, include the following: