Author
- Isabella I of Castile1
- Isobel Salcedo Larralde1
- Ja'far Kashfi1
- Jacobus de Cessolis1
- Jaghmini1
- Jakob Wimpfeling1
- Jalal al-Din al-Suyuti1
- Jalaluddin al-Mahalli1
- Jawād ibn Saʻd Jawād al-Baghdādī1
- Jean Manesca1
- Jean de Wavrin1
- Jerónimo Román y Zamora1
- Joannes de Crivelli1
- Johann Herolt1
- Johannes Gherinx1
- Johannes Paulus1
- Johannes ab Indagine1
- Johannes von Freiburg1
- John Bale1
- John Fortescue1