- Jewish physicians1
- Jews, Italian1
- Jews--Persecutions1
- Jiří, z Poděbrad, King of Bohemia, 1420-14711
- Joachim, Saint1
- Joannes de Caligariis1
- Job (Biblical figure)1
- Johannes filius Roberti de Cruce1
- John IV, King of Portugal, 1604-16561
- John Manuel, Prince of Portugal, 1537-15541
- John V, King of Portugal, 1689-17501
- John VIII Palaeologus, Emperor of the East, 1392-14481
- John the Baptist's Day1
- Jonah (Biblical prophet)1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism (Christian theology)1
- Judaism--Liturgy1
- Judas Iscariot1
- Judges1
- Judges--Selection and appointment1