Author
- Joannes Oliva1
- John Burgh1
- John Cassian1
- John Felton1
- John Gage1
- John Gower1
- John Larry England1
- John Mandeville1
- John of Glastonbury1
- John of Wales1
- Joseph Angelet1
- Joseph ben Abraham Gikatilla1
- Joseph ben Judah ibn Aknin1
- Juan Antonio de Hozes Sarmiento1
- Judah ben Saul ibn Tibbon1
- Julian of Toledo1
- Julius II1
- Jullien Gervais1
- Kingdom of England1
- Lactantius1