Encyclopedias, Almanacs, Transcripts, and Maps
- Ahmad Ibn Idris (1750–1837)
- Ahmad Khan, (Sir) Sayyid (1817–1898)
- Ahmad, Mirza Ghulam (Late 1830s–1908)
- Ahmadiyya
- Ahrweiler
- Ahura Mazda (Ohrmazd) and Ahriman
- Ahwaz
- Ai or Ha-Ai
- Ai T'Ien (b. c. 1545)
- Aibu
- Aichinger, Ilse
- Aidan of Lindisfarne, St.
- Aiguani, Michele (Anguani, Angriani)
- Aigulf of Lérins, St.
- Aiken, Henry David
- Aikenhead, Mary
- Aikhenvald Yuli Isayevich
- Aimeric of Piacenza
- Ain-Traz, Synods of
- Ainay, Abbey of