- Japan1
- Japanese poetry1
- Jawī Zādah, Muḥammad ibn Ilyās, -1547 or 1548. Risālah fī al-masḥ ʻalá al-khuffayn1
- Jaʻbarī, Arslān ibn Yaʻqūb, -1300. Risālat al-tawḥīd1
- Jerónima de la Asunción, madre, 1555-16301
- Jesuit drama, Spanish1
- Jesuits1
- Jewish astronomy1
- Jewish courts1
- Jewish festival-day sermons1
- Jewish magic1
- Jewish poetry1
- Jewish religious poetry, Judeo-Arabic1
- Jewish travelers1
- Jews--Medicine1
- Jihad1
- Jinn1
- John I, King of Portugal, 1357-14331
- John VIII Palaeologus, Emperor of the East, 1392-14481
- Joseph Della Reina, active 15th century1