Saint Mary's Parish was the town of Grantville's native Catholic church. Before the Ring of Fire, it was called Saint Vincent de Paul's, which created an awkward situation after Grantville landed in the past, as Vincent de Paul was still alive in 1631, and not all that highly regarded outside of France. Thus, it became St. Mary's. The parish priest, Father Lawrence Mazzare, became famous after dispatches from the various spies sent into the alien town almost always reported on the Catholic parish, its priest, and how well they get along with the many Protestant sects and Jews.