Author
- Innocent III1
- Isaac Alfasi1
- Isaac ben Joseph of Corbeil1
- Ismail al-Isfahani1
- Izz al-Din ibn 'Abd al-Salam1
- Izz al-Din ibn Hibatullah ibn Abi l-Hadid1
- Jacob ben Asher1
- Jacobus de Cessolis1
- Jacopo Piccolomini-Ammannati1
- Jacques Lempereur1
- Jaghmini1
- Jalal Al-Din Al-Khabazi1
- Jalaluddin al-Mahalli1
- Jami1
- Jamāl al-Dīn Aḥmad ibn Muḥammad Ẓāhirī1
- Jamāl al-Dīn Ḥaṣīrī1
- Jean Dupin1
- Jean de Lignieres1
- John Gower1
- John Larry England1