| Diocese | St. Catharines |
| City | Parish (Catholic Population of the Parish) |
| Wainflett | Mission St. Therese (50) |
| St. Catharines | Queen of Angels Oratory (100) |
| Thorold | St. Aloysius (250) |
| Dunnville | St. Michael (1500) |
| St. Catharines | Our Lady of Perpetual Help (3000) |