Perry County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 45,969. The county seat is New Bloomfield. The county was created on March 22, 1820, and was named after Oliver Hazard Perry, a hero of the War of 1812, who had recently died. It was originally part of Cumberland County and was created in part because residents did not want to travel over the mountain to Carlisle (the county seat of Cumberland County), and thus the temporary county seat became Landisburg (before New Bloomfield was chosen.)
Perry County is included in the Harrisburg-Carlisle, PA Metropolitan Statistical Area. The county is served by the 717/223 area codes.
In 2010, the center of population of Pennsylvania was located in the eastern end of Perry County. Green Park, an incorporated village located in northeastern Tyrone Township, serves as Perry County's midpoint between the Conococheague Mountain in the west and the Susquehanna River to the east.