- Jews--Persecutions1
- Jiménez de Cisneros, Francisco, 1436?-15171
- John I, King of Portugal, 1357-14332
- John II, King of Aragon, 1397-14791
- John, the Apostle, Saint1
- Joseph (Son of Jacob)3
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism1
- Judaism--Ari rite1
- Judaism--Liturgy2
- Judaism--Liturgy--Texts2
- Judgment Day1
- Justinian I, Emperor of the East, 483?-5651
- Jābir ibn Ḥayyān1
- Jānakīnātha Bhaṭṭācārya, active 16th century. Nyāyasiddhāntamañjarī2
- Karaites1
- Karma12
- Kashmir Śaivism3
- Kashmir Śaivism--Doctrines1
- Kavaca1