Author
- 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 Glastonbury1
- John of Howden1
- John of Saxony1
- João Freire1
- Juana I of Castile1
- Julianus Pomerius1
- Julius II1
- Julius III1
- Kollegium Sankt Nikolaus1
- Konrad von Brundelsheim1
- Lambert le Bègue1
- Leon Battista Alberti1