- Jiménez de Enciso family1
- Jiménez de Enciso, Andrés1
- Jiménez de Enciso, Diego1
- Jiménez de Enciso, Pedro1
- Joachim, Saint1
- John I, King of Portugal, 1357-14331
- John II, King of Aragon, 1397-14791
- John II, King of Portugal, 1455-14951
- John, King of England, 1167-12161
- John, the Apostle, Saint2
- Joseph (Son of Jacob)1
- Juana, la Loca, Queen of Castile, 1479-15552
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism2
- Judaism--Ari rite1
- Judaism--Liturgy2
- Judaism--Liturgy--Texts2
- Judaism--Prayers and devotions1
- Judeo-Arabic literature1
- Judeo-Persian language1