Hardin County was formed in 1851. It was named after Colonel John J. Hardin, who died in the Mexican–American War.
In its history the county has had three courthouses. The first
was a small wood framed building, which burned down in the 1850s. The
second courthouse was a two-story building and stood on the site of the
current office of the county sheriff. The third and present courthouse
was constructed in 1892 and opened on September 19, 1893. The
structure was listed on the National Register of Historic Places in
Hardin County, along with Story County, was also a primary filming location for the 1996 movie Twister, starring Bill Paxton and Helen Hunt.