- Repentance--Islam1
- Requesens, Antonio de'1
- Requesens, Berengario de'1
- Requesens, Bernardo de'1
- Requesens, Giuseppe de'1
- Ressano, Catterina1
- Ressano, Giovanni1
- Riddles, Arabic1
- Riddles, Persian1
- Right of property (Islamic law)1
- Risālah (Ibn Abī Zayd al-Qayrawānī, ʻAbd Allāh ibn ʻAbd al-Raḥmān)1
- Roderick, King of the Visigoths, -711?1
- Romances1
- Rome (Empire)1
- Rüstem Paşa Camii (Istanbul, Turkey)1
- Rāgamālā painting1
- Samaritans1
- Samarqandī, Muḥammad ibn Ashraf, active 13th century. Risālah fī ādāb al-baḥth1
- Sancho II, King of Castile and Leon, 1037 or 1038-10721
- Sancho IV, King of Castile and Leon, 1257-12951