- Alexander Balas, King of Syria, -145 B.C.1
- Alexander, de Villa Dei. Doctrinale puerorum1
- Alum tawed thongs (Bindings)1
- Ambrose, Saint, Bishop of Milan, -3971
- Ambrosian rite (Catholic Church)1
- Amelius, Martyr1
- Amicus, Martyr1
- Andria (Terence)1
- Anecdotes1
- Angels1
- Angels--Christianity1
- Angels--History of doctrines1
- Animals1
- Anselm, Saint, Archbishop of Canterbury, 1033-11091
- Anthony, of Egypt, Saint, approximately 250-355 or 3561
- Anti-Catholicism1
- Anticlaudianus (Alanus, de Insulis)1
- Antiphonaries--Manuscripts1
- Antonius, de Parma, active 1310-13231
- Apocalpytic literature1