- Ji bu--Zong ji lei--Cong bian1
- Jihad1
- Jinn2
- John I, King of Portugal, 1357-14331
- John VIII Palaeologus, Emperor of the East, 1392-14481
- John the Baptist's Day1
- Joseph (Son of Jacob)2
- Joseph Della Reina, active 15th century1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism12
- Judaism--Customs and practices4
- Judaism--Liturgy4
- Judaism--Prayers and devotions2
- Judeo-Arabic language2
- Judeo-Arabic literature8
- Judges (Islamic law)1
- Judgment Day (Islam)3
- Judicial power (Islamic law)1
- Julius III, Pope, 1487-15551
- Jumʻah6