Old St. Joseph's Church was the first Roman Catholic church in Philadelphia, Pennsylvania, U.S. When it was founded in 1733, Old St. Joseph's Church was the only place in the English-speaking World where public celebration of the holy sacrifice of the Mass was permitted by law. In 1734, the right of Catholics to worship in Pennsylvania was challenged.
The religious liberty of Catholics was affirmed by the Pennsylvania Provincial Assembly under William Penn's Charter of Privileges. Old St. Joseph's Church was founded by Fr. Joseph Greaton, an English Jesuit. The current church, on Willings Alley in the Society Hill neighborhood of Philadelphia, the third church on the site, was built in 1839. St. Joseph's University and St. Joseph's Preparatory School were founded at Old St. Joseph's.