Author
- Joan Martines1
- Johannes Hymmonides1
- Johannes von Freiburg1
- John Capgrave1
- John Davnay1
- John Larry England1
- John Mandeville1
- John Shirley1
- John Tiptoft, 1st Earl of Worcester1
- John Wycliffe1
- John XXII1
- John de Breton1
- John de Seccheville1
- John of Damascus1
- John of Howden1
- John of Saxony1
- Joseph ben Judah ibn Aknin1
- Judah ben Saul ibn Tibbon1
- Julianus Pomerius1
- Jullien Gervais1