Author
- Johannes Lichtenberger1
- Johannes Mellarinus1
- Johannes Schöner1
- Johannes Tostius1
- Johannes von Kastl1
- John Burgh1
- John Cornelius1
- John Felton1
- John Frederick II of Saxony1
- John Speidell1
- John XXI1
- John of Ibelin1
- John Dokeianos1
- Joseph ben Moses Sarfati1
- Juan de Torquemada1
- Jullien Gervais1
- Kamāl al-Dīn Turkumānī1
- Konrad III. von Soltau1
- Laurent d'Orleans1
- Laurentius Cynthius1