The Old Franklin County Jail is a historic jail located at Chambersburg in Franklin County, Pennsylvania. It was built in 1818, and is a two-story, brick building with a slate covered hipped roof topped by a cupola. The original building measures 84 feet wide by 48 feet deep. In 1880, a cell block was added. The jail yard is divided into two sections and surrounded by a 20-foot-high wall. At least five prisoners were hanged on the premises.