Author
- Isaac Lopez1
- Isaac Sasportas1
- Isaac ben Joseph of Corbeil1
- Isaac of Troki1
- Isaiah di Trani1
- Isidore of Seville1
- Ismail bin Mohammad Rizi1
- Ismāʻīl Jarrāḥī1
- Ismāʻīl ibn Abī Bakr Ibn al-Muqrī1
- Ismāʻīl ibn Aḥmad Ibn al-Athīr1
- Issachar ben Mordecai ibn Susan1
- Jabir ibn Hayyan1
- Jacob ben Jacob, ha-Kohen, -approximately 12701
- Jacob ben Machir ibn Tibbon1
- Jacobo Bellenden1
- Jacobus Dinetus1
- Jacobus de Teramo1
- Jacobus de Voragine1
- Jacopo Ragone1
- Jagannatha Panditaraja1