Author
- John Cassian1
- John Cornelius1
- John Dominici1
- John Felton1
- John Fortescue1
- John Gage1
- John Gower1
- John Larry England1
- John XXI1
- John XXII1
- John of Glastonbury1
- Jordan von Quedlinburg1
- Joseph Angelet1
- Joseph Nasi1
- Joseph Trani1
- Joseph ben Judah ibn Aknin1
- Joseph ben Moses Sarfati1
- Joseph ibn Migash1
- Josephus1
- Joshua ben Israel Benveniste1