Author
- Johannes Paulus1
- Johannes ab Indagine1
- Johannes von Freiburg1
- Johannes von Kastl1
- John Burgh1
- John Dominici1
- John Felton1
- John Gower1
- John XXI1
- John of Glastonbury1
- Jordan von Quedlinburg1
- Joseph Angelet1
- Joseph ben Abraham Gikatilla1
- Joseph ben Moses Sarfati1
- Josephus1
- Juan de Torquemada1
- Judah ben Saul ibn Tibbon1
- Jullien Gervais1
- Junayd ibn Sandal Baghdādī1
- Jörg Muelich1