- Jiménez de Enciso, Pedro1
- John, Duke of Burgundy, 1371-14191
- John, the Apostle, Saint1
- Juana, la Loca, Queen of Castile, 1479-15551
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism3
- Judeo-Arabic language2
- Judges (Islamic law)1
- Judges--Selection and appointment1
- Julius III, Pope, 1487-15552
- Justice, Administration of2
- Jāmiʻ al-Azhar5
- Jāmiʻ al-Muẓaffarī (Damascus, Syria)1
- Jāmiʻ al-ṣaḥīḥ (Bukhārī, Muḥammad ibn Ismāʻīl)1
- Jāmiʻ al-ṣaḥīḥ (Muslim ibn al-Ḥajjāj al-Qushayrī)1
- Kanz al-wuṣūl ilá maʻrifat al-uṣūl (Bazdawī, ʻAlī ibn Muḥammad)1
- Kashshāf (Zamakhsharī, Maḥmūd ibn ʻUmar)2
- Khabbāzī, ʻUmar ibn Muḥammad, 1231 or 1232-1292. Mughnī fī uṣūl al-fiqh1
- Khaṭīb al-Baghdādī, Abū Bakr Aḥmad ibn ʻAlī, 1002-1071. Asmāʼ al-mubhamah fī al-anbāʼ al-muḥkamah1
- Kings and rulers3