- Jesuit drama, Spanish1
- Jesuits1
- Jewelry1
- Jewish astronomy1
- Jewish calendar1
- Jewish courts1
- Jewish illumination of books and manuscripts1
- Jewish interpretations of Jesus Christ1
- Jewish magic1
- Jewish religious poetry, Judeo-Arabic1
- Jews--Medicine1
- Ji bu--Bie ji lei--Yuan1
- Ji bu--Zong ji lei--Cong bian1
- Jinn1
- John I, King of Portugal, 1357-14331
- John VIII Palaeologus, Emperor of the East, 1392-14481
- John the Baptist's Day1
- Joseph Della Reina, active 15th century1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judges (Islamic law)1