Author
- Innocent V2
- Jacobus de Cessolis2
- Jacopo Piccolomini-Ammannati2
- Jacopone da Todi2
- James of Lausanne2
- Joannes Oliva2
- Johann Herolt2
- Johannes Nider2
- John Burgh2
- John Cassian2
- John Halgren of Abbeville2
- John XXII2
- John of Genoa2
- Jordan von Quedlinburg2
- Julian of Toledo2
- Julianus Pomerius2
- Julius II2
- Justin2
- Kingdom of England2
- Konrad III. von Soltau2