Author
- Innocent IV1
- Isidore of Seville1
- Jacobus de Voragine1
- Jaimini1
- Jalal al-Din al-Qazwini1
- James of Milan1
- Jayāditya1
- Jean Bénard1
- Jean Dupin1
- Jean de Roquetaillade1
- Jerome de Prado1
- Joachim Bendel1
- Johann Hertzhaimer1
- Johannes Auerbach1
- John Chrysostom1
- John Montgomery1
- John Wycliffe1
- John de Beauchesne1
- João Gomes da Silva1
- Julius III1