Pennsylvania Parish Founding Dates
Pennsylvania – Delaware County – Spinoffs from St. Thomas The Apostle
Pennsylvania
| Founding Year | Parish | Diocese |
| 1729 | St. Thomas The Apostle at Ivy Mills | Philadelphia |
| 1730 | Sacred Heart (Conewago Chapel) | Harrisburg |
| 1733 | Old St. Joseph | Philadelphia |
| 1741 | Most Blessed Sacrament (First known as the Mission of Goshenhoppen in Bally, then as St. Paul) |
Allentown |
| 1763 | Old St. Mary | Philadelphia |
| 1790 | Saint Vincent | Greensburg |
| 1799 | St. Michael | Altoona/Johnstown |
| 1808 | Saint Patrick | Pittsburgh |
| 1830 | Saint Francis (Clearfield) | Erie |
| 1853 | Saint Vincent | Scranton |
Delaware County
| Founding Year |
Parish | Location |
| 1825 | Saint Denis | Havertown |
| 1842-1993 | Saint Michael | Chester |
| 1849 | St. Charles Borromeo | Drexel Hill |
Parishes Formed From St. Thomas The Apostle
at Ivy Mills
| Founding Year |
Parish | Location |
| 1868 | Nativity of the Blessed Virgin Mary | Media |
| 1869 | Saint Patrick | Kennett Square |
| 1894 | Saint Francis de Sales | Lenni |
| 1963 | Saint Cornelius | Chadds Ford (then Birmingham) |
| 1971 | Saint John Fisher | Boothwyn |
| 1986 | Saint Maximilian Kolbe | Westtown |
Lists compiled by Kathy McNichol & Marianne Squyres
2005, 2012