- John Manuel, Prince of Portugal, 1537-15541
- John V, King of Portugal, 1689-17501
- John VIII Palaeologus, Emperor of the East, 1392-14481
- John, Duke of Burgundy, 1371-14191
- John, King of England, 1167-12161
- John, of Damascus, Saint1
- John, the Apostle, Saint1
- John, the Baptist, Saint1
- Judas Iscariot1
- Judeo-Italian language1
- Judgment Day1
- Judicial power (Islamic law)1
- Juhd al-muqill (Sājaqlīzādah, Muḥammad ibn Abī Bakr)1
- Julius III, Pope, 1487-15551
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Risālah al-kubrá fī al-manṭiq1
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Sharḥ Farāʼiḍ al-Sirājīyah1
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Ḥāshiyah ʻalá Maṭāliʻ al-anẓār1
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Ḥāshiyah ʻalá Sharḥ Ḥikmat al-ʻayn1
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Ḥāshiyah ʻalá Taḥrīr al-Qawāʻid al-manṭiqīyah1
- Jurjānī, ʻAlī ibn Muḥammad, al-Sayyid al-Sharīf, 1340-1413. Ḥāshiyah ʻalá al-Muṭawwal1