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).