St. Joseph's Preparatory School, known as "St. Joe’s Prep" or simply "The Prep", is an urban, private, Catholic, college preparatory school run by the Jesuits in Philadelphia, Pennsylvania, United States. The school was founded in 1851 from the Old St. Joseph's Church in the city's Society Hill neighborhood. The school moved to its current campus on Girard Avenue in the 1870s with the construction of the Church of the Gesu.

Old St. Joseph's Church is a church in Philadelphia, Pennsylvania, and was the first Roman Catholic church in the city. The church was founded in 1733; the current building was dedicated in 1839.