- Pratyakṣakhaṇḍa (Gaṅgeśa)1
- Predestination (Islam)1
- Quṭb al-Shīrāzī, Maḥmūd ibn Masʻūd, 1236 or 1237-1310 or 1311. Sharḥ Ḥikmat al-ishrāq1
- Rainbows1
- Religious life--Islam1
- Rudra (Hindu deity)1
- Rāma (Hindu deity)1
- Samarqandī, Abū al-Qāsim ibn Abī Bakr, active 15th century. Risālah al-Samarqandīyah fī al-istiʻārāt1
- Samarqandī, Muḥammad ibn Ashraf, active 13th century. Risālah fī ādāb al-baḥth1
- Satellites--Phases1
- Shamsīyah (Qazwīnī, ʻAlī ibn ʻUmar)1
- Sharḥ al-Mawāqif (Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf)1
- Sharḥ al-Qūshjī ʻalá Tajrīd al-ʻaqāʼid lil-Ṭūsī (Qūshjī, ʻAlī ibn Muḥammad)1
- Soul--Christianity1
- Soul--Islam1
- Spain1
- Spirituality1
- Spirituality--Middle Ages1
- Sufism--Doctrines1
- Sullam al-ʻulūm (Bahārī, Muḥibb Allāh ibn ʻAbd al-Shakūr)1