| What it was about | Encyclical | Year |
| The need for the practice of interior and exterior penance | |
| Establishing universal peace in truth, justice, charity, and liberty | |
| Commemorating the fifteenth centenial of the death of Pope St. Leo I: The see of peter as the center of christian unity | |
| Christianity and social progress | |
| The missions, native clergy, and lay participation | |
| The Rosary: Prayer for the Church, missions, international and social problems | |
| St. John Vianney | |
| Truth, unity, and peace, in a spirit of charity | |
|