- Ambrose, Saint, Bishop of Milan, -3971
- Ambrosian rite (Catholic Church)1
- Amelius, Martyr1
- Amicus, Martyr1
- Anecdotes1
- Animals1
- Anne (Mother of the Virgin Mary), Saint1
- Annunciation to the Blessed Virgin Mary1
- Anselm, Saint, Archbishop of Canterbury, 1033-11091
- Anticlaudianus (Alanus, de Insulis)1
- Antiphonaries--Manuscripts1
- Antiquities1
- Antonio Magistri1
- Apocryphal Gospels1
- Apocryphal and legendary literature1
- Apocryphal books1
- Apocryphal books (New Testament)1
- Apparitions1
- Arbalet, Jean1
- Arithmetic--Study and teaching1