- Alfonso V, King of Aragon, 1396-14581
- Alliata family1
- Almanach perpetuum celestium motuum (Zacuto, Abraham ben Samuel)1
- Altoviti, Bartolomea1
- Alum tawed thongs (Bindings)1
- Amadori, Lorenzo1
- Ambrogio, Leonardo d'1
- Ambrose, Saint, Bishop of Milan, -3971
- Ambrosian rite (Catholic Church)1
- Amedei, Bartolomeo1
- Amelius, Martyr1
- Amicus, Martyr1
- Amideo, Chele d'1
- Andrea, Antonio di1
- Andrea, Fabiano di1
- Andrea, Michele di1
- Andrea, Piero di1
- Andrea, Pietro di1
- Andreucci, Bartolomeo1
- Andrew, Apostle, Saint1