Author
- Johannes von Werdea1
- Johannis Hieronymus1
- John Capgrave1
- John Cleseby1
- John Felton1
- John Halgren of Abbeville1
- John Shirley1
- John Tiptoft, 1st Earl of Worcester1
- John Versor1
- John Wycliffe1
- John XXI1
- John of Glastonbury1
- John of Howden1
- John of Seville ?1
- Juan de Torquemada1
- Julianus Pomerius1
- Justin1
- Justinian I1
- Jörg Muelich1
- Kingdom of England1