| Hilarius (Saint —) |
| Hippolytus (Saint —) |
| Homobonus (Saint —) |
| Honoratus (Saint —) |
| Honorina (Saint —) |
| Hugh (Saint —) |
| Ignatius (Saint —) |
| Immaculate Conception |
| Invention of the Holy Cross |
| Ioan Botezătorul (Saint —) |
| Isabel of France (Saint —) |
| Isidore (Saint —) |
| Isidore, the Farmer |
| James (Saint —) |
| January 10th |
| January 1st |
| January 20th |
| January 2nd |
| January 9th |
| Jerome (Saint —) |