- John VIII Palaeologus, Emperor of the East, 1392-14481
- Joseph (Son of Jacob)1
- Judaism1
- Judaism--Ari rite1
- Judaism--Prayers and devotions1
- Judeo-Arabic language1
- Judeo-Persian language1
- Julius III, Pope, 1487-15551
- Jurisprudence1
- Jābir ibn Ḥayyān1
- Jāmiʻ al-Azhar1
- Jāmiʻ al-Muẓaffarī (Damascus, Syria)1
- Jāmiʻ al-ṣaḥīḥ (Bukhārī, Muḥammad ibn Ismāʻīl)1
- Kanz al-daqāʼiq (Nasafī, ʻAbd Allāh ibn Aḥmad)1
- Karaite manuscripts1
- Kashshāf (Zamakhsharī, Maḥmūd ibn ʻUmar)1
- Kavvanot (Cabala)1
- Kaʻbah (Mecca, Saudi Arabia)1
- Kemalpaşazade, 1468 or 1469-15341
- Kirchmair, Georg, 1481-15541