On February 12, 1820, the Ohio government authorized the creation of Hardin County. Residents named the county in honor of John Hardin, a hero of the American Revolution. Previously, the county had been part of land reserved to Ohio's Indian people, under the Treaty of Greenville.
Hardin County is located in northwestern Ohio. It is predominantly rural, with less than one percent of the county's 470 square miles consisting of urban areas. The county seat is Kenton, named for backwoodsmen Simon Kenton. With a population of 8,336 people, Kenton was the county's largest community in 2000. Many residents of Ohio's rural communities are seeking better lives and more opportunities in the state's cities, but Hardin County's population seems to be remaining stable. The county experienced a 2.7 percent population growth rate between 1990 and 2000, bringing the total number of residents up to 31,945. The county averages sixty-eight people per square mile.
Farming is the largest employer in Hardin County, with manufacturing businesses and retail positions following closely behind. In 1999, the per capita income in the county was almost twenty thousand dollars, with 11.5 percent of the people living in poverty.
Most voters in Hardin County claim to be independents, yet in recent years, they have overwhelmingly supported Republican Party candidates at the national level.
The county is home to Ohio Northern University.