Devon Preparatory School is a private, Catholic college preparatory school in Devon, Pennsylvania, founded in 1956 by the Piarist fathers. It is an all-boys school, divided into a middle school (grades 6–8) and an upper school (grades 9–12), both located on the same campus of 20 acres (81,000 m2). The school operates independently with the blessings of the Roman Catholic Archdiocese of Philadelphia.The mansion, the centerpiece of the estate, was built in 1913 by Philadelphia publisher Dr.