- Arbaʻah ṭurim (Jacob ben Asher)1
- Arbitration agreements, Commercial1
- Archangels1
- Archery1
- Architecture1
- Architecture, Roman1
- Architecture--Orders1
- 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
- Ardinghelli, Rinaldo degli1
- Arianism1
- Aringhello, Tommaso di1
- Aristotle. Theologia1
- Arithmetic--Study and teaching1
- Ark of the Covenant1
- Arma Christi1
- Armada (1588)1
- Armaiolo, Puccino1
- Armaleoni, Benedetto degli1