- Adrian VI, Pope, 1459-15231
- Aegidius, Saint, Abbot1
- Affinity (Law)1
- Agamemnon, King of Mycenae (Mythological character)1
- Agazaria, Claudio Boncompagni di1
- Agreda, Dominici d'1
- Alban, Saint, -304?1
- Albertus de Fontanella1
- Albigenses1
- Albizzi, Costanza1
- Alchemy--Bibliography1
- Aldobrandini, Giovanni degli1
- Aleramo, Marquis of Monferrato, -9671
- Alessandri, Alessandro degli1
- Alessandri, Niccolò degli1
- Alessandro, Pietro di1
- Alexander, the Great, 356 B.C.-323 B.C.1
- Alfonso V, King of Aragon, 1396-14581
- Alliata family1
- Altoviti, Bartolomea1