- Italy--Ferrara1
- Italy--Padua1
- Italy--Perugia1
- Italy--Siena1
- Jesuits1
- Jews1
- John IV, King of Portugal, 1604-16561
- John Manuel, Prince of Portugal, 1537-15541
- John V, King of Portugal, 1689-17501
- John the Baptist's Day1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism--Controversial literature1
- Judgment Day1
- Julian, of Eclanum, Bishop, 380-approximately 4551
- Julius III, Pope, 1487-15551
- Kekchi language1
- Kings and rulers1
- Knowledge, Theory of (Religion)1
- Kölner Dom1
- Lafões, Pedro Henrique de Bragança, Duque de, 1718-17611