- Jārūdī, Nāṣir ibn Muḥammad, active 18th century1
- Jīlī, ʻAbd al-Karīm ibn Ibrāhīm, 1365 or 1366- Risālat al-Tawḥīd1
- Kabāʼir (Muḥammad ibn ʻAbd al-Wahhāb)1
- Kanz al-daqāʼiq (Nasafī, ʻAbd Allāh ibn Aḥmad)1
- Karaite calendar1
- Karaite philosophy1
- Karaites--Doctrines1
- Karaitic literature1
- Karmī, Marʻī ibn Yūsuf, -1623 or 16241
- Kashmir Śaivism--Doctrines1
- Kavaca1
- Kaʻb al-Aḥbār, -655 or 6561
- Khabīṣī, Muḥammad ibn Abī Bakr, active 14th century. Muwashshaḥ1
- Khafrī, Muḥammad, -1407 or 1408. Ḥāshīyah ʻalá Sharḥ al-Qūshjī ʻalá al-Tajrīd1
- Khamrīyah (Ibn al-Fāriḍ, ʻUmar ibn ʻAlī)1
- Kharijites1
- Khiḍr (Legendary character)1
- Kings and rulers--Religious aspects--Hinduism1
- Kisāʼī, ʻAlī ibn Ḥamzah, -804 or 8051
- Knowledge, Theory of (Hinduism)1