- Almanach perpetuum celestium motuum (Zacuto, Abraham ben Samuel)1
- Amadori, Bartolomeo1
- Amadori, Lorenzo1
- Amadori, Niccolo1
- Annotations1
- Antenuptial contracts (Jewish law)1
- Anthony, of Padua, Saint, 1195-12311
- Aramaic language1
- Arcispedale Santa Maria Nuova (Reggio Emilia, Italy)1
- Arrigucci, Andrea1
- Arrigucci, Donato1
- Astronomy, Medieval1
- Atlases (Geographic)1
- Attila, -4531
- Augustinians1
- Augustus, Emperor of Rome, 63 B.C.-14 A.D.1
- Autographs1
- Azar, Menaḥem ben Natan1
- Baptism--Catholic Church1
- Bar mitzvah1