- Jābir ibn Ḥayyān1
- Jāmiʻ al-Azhar1
- Jāmiʻ al-Muẓaffarī (Damascus, Syria)1
- Jāmiʻ al-Umawī al-Kabīr (Aleppo, Syria)1
- Jārabardī, Aḥmad ibn al-ḥusayn, d. 1346. Sharḥ al-Shāfiyah1
- Kalāʼī, Muḥammad ibn Sharaf, d. 13751
- Karaites1
- Karaites--Liturgy1
- Kavvanot (Cabala)1
- Kaʻbah (Mecca, Saudi Arabia)1
- Kemalpaşazade, 1468 or 1469-15341
- Khabbāzī, ʻUmar ibn Muḥammad, 1231 or 2-1292. Mughnī fī uṣūl al-fiqh1
- Khawāfī, Muḥammad ibn Muḥammad, 1356-1435. Awrād al-Zaynīyah1
- Kifāyat al-ḥuffāẓ (Ibn al-Hāʼim, Aḥmad ibn Muḥammad)1
- Kings and rulers--Heraldry1
- Kirchmair, Georg, 1481-15541
- Lafões, Pedro Henrique de Bragança, Duque de, 1718-17611
- Land grants1
- Land value taxation1
- Languages, Secret1