Author
- Johannes Schöner1
- Johannes Tostius1
- Johannes de Sacrobosco1
- Johannes von Kastl1
- John Chrysostom1
- John Cornelius1
- John Frederick II of Saxony1
- John II of Castile1
- John XXI1
- John of Ibelin1
- John Dokeianos1
- Joseph ben Ephraim Karo1
- Joseph ben Moses Sarfati1
- Joshua Benzion Segre1
- Juan de Torquemada1
- Juana I of Castile1
- Jñānamṛtapata1
- Kalyanamalla1
- Kanada1
- Kauśikarāma1