Author
- Jacques de Vitry1
- Jean de Meun1
- Jean-François Roussin1
- Joan Martines1
- John Burgh1
- John Capgrave1
- John Cassian1
- John Gower1
- John Lydgate1
- John Tiptoft, 1st Earl of Worcester1
- João Freire1
- Julian of Toledo1
- Julianus Pomerius1
- Julius II1
- Justinian I1
- Kingdom of England1
- Lactantius1
- Leon Battista Alberti1
- Leontios of Neapolis1
- Lorenzo Belo1