- Iṣfahānī, Maḥmūd ibn ʻAbd al-Raḥmān, 1275 or 1276-1348 or 1349. Tashyīd al-Qawāʻid1
- Iẓhār al-asrār (Birgivî Mehmet Efendi)1
- Jerome, Saint, -419 or 4201
- Jidd Ḥafṣī, ʻAlī ibn Luṭf Allāh, active 17th century-18th century1
- Jāmiʻ al-ṣaḥīḥ (Bukhārī, Muḥammad ibn Ismāʻīl)1
- Jāmiʻ al-ṣaḥīḥ (Muslim ibn al-Ḥajjāj al-Qushayrī)1
- Jāmī, 1414-1492. Poems1
- Jāmī, 1414-1492. Tafsīr al-fātiḥah al-sharīfah1
- Jārūdī, Nāṣir ibn Muḥammad, active 18th century1
- Jīlī, ʻAbd al-Karīm ibn Ibrāhīm, 1365 or 1366- Risālat al-Tawḥīd1
- Kapitalbünde1
- Karmī, Marʻī ibn Yūsuf, -1623 or 16241
- Kaʻbah (Mecca, Saudi Arabia)1
- Kemalpaşazade, 1468 or 1469-15341
- Khalwatīyah1
- Khānaqāh-i Niʻmat Allāhī1
- Kings and rulers--Religious aspects1
- Kinship (Islamic law)1
- Knowledge, Theory of (Islam)1
- Latin language, Medieval and modern1