Author
- Isaac Newton3
- Ishmael ben Abraham Isaac ha-Kohen3
- Iskandar Beg Munshi3
- Ismāʻīl Ghāzānī3
- Isḥāq ibn Ḥasan Tūqādī3
- Ivo of Chartres3
- Jacob Anatoli3
- Jacques Legrand3
- Jalal Al-Din Al-Khabazi3
- Jayadeva3
- Jean Gerson3
- Jean de Meun3
- Jewish Community of Carpentras, France3
- John Cassian3
- John of Wales3
- Josephus3
- Kınalızâde Hasan Çelebi3
- Laugākṣi Bhāskara3
- Leo Archpriest3
- Leo I3