- Arbaʻah ṭurim (Jacob ben Asher)1
- Arbaʻūn al-Nawawīyah (Nawawī)4
- Archangels1
- Archery1
- Archery in literature2
- Architecture2
- Architecture, Roman1
- Architecture--Orders1
- Archives90
- Arcibucci, Alessandro1
- Ardabīlī, Aḥmad ibn Muḥammad, -1585. Majmaʻ al-fāʼidah wa-al-burhān fī sharḥ Irshād al-adhhān1
- Ardabīlī, Muḥammad ibn ʻAbd al-Ghanī, -1249 or 1250. Sharḥ al-Unmūdhaj1
- Ardabīlī, Muḥammad ibn ʻAbd al-Ghanī, 1572-1627. Sharḥ al-Unmūdhaj6
- Ardinghelli, Rinaldo degli1
- Argonauts (Greek mythology)1
- Arianism2
- Aringhello, Tommaso di1
- Aristotle25
- Aristotle. Nicomachean ethics1
- Aristotle. Theologia1