Author
- Hugh of Fouilloy1
- Immanuel Bonfils1
- Innocent III1
- Jacobus de Voragine1
- Jacques de Vitry1
- Jean Dupin1
- Jean Germain1
- Jean de Wavrin1
- Jean-François Roussin1
- Joan Martines1
- John Burgh1
- John Capgrave1
- John Cassian1
- John Chrysostom1
- John Gower1
- John Tiptoft, 1st Earl of Worcester1
- Joseph Haslewood1
- Juan Páez de Castro1
- Julian of Toledo1
- Julianus Pomerius1