It was named for the first Governor of Indiana and a nine-term congressman, Jonathan Jennings.

The county is located in the center of an imaginary triangle consisting of Indianapolis, IN, Cincinnati, OH, and Louisville, KY and requires only 11⁄4 hour drive time to any of these urban centers.

It is also home to the Muscatatuck Urban Training Center, located just outside North Vernon, at which various training exercises and scenarios are conducted for homeland security and other similar purposes.

They are responsible for setting salaries, the annual budget, and special spending.

The commissioners are charged with executing the acts legislated by the council, collecting revenue, and managing the day-to-day functions of the county government.

The judge on the court is elected to a term of four years and must be a member of the Indiana Bar Association.

[10] County Officials: The county has several other elected offices, including sheriff, coroner, auditor, treasurer, recorder, surveyor, and circuit court clerk Each of these elected officers serves a term of four years and oversees a different part of county government.

[10] Jennings County is part of Indiana's 6th congressional district and is represented in Congress by Republican Greg Pence.

Democratic presidential candidates have won Jennings County only thrice in the past 130 years.

As of the 2010 United States Census, there were 28,525 people, 10,680 households, and 7,733 families residing in the county.