Author
- Ibn al-Tayyib1
- Ibrāhīm Shabistarī1
- Ibrāhīm ibn Hibat Allāh Lakhmī1
- Ibrāhīm ibn Muḥammad Ṣafāqisī1
- Ibrāhīm ibn ʻAlī Ṭaraṣūṣī1
- Ikhtiyār al-Dīn ibn Ghiyāth al-Dīn1
- Inayet Efendi1
- Isaac Newton1
- Isfarāyīnī, Muḥammad ibn Muḥammad, d. 13461
- Issachar ben Mordecai ibn Susan1
- Isḥāq ibn Yūsuf Ṣardafī1
- Izz al-Din ibn Hibatullah ibn Abi l-Hadid1
- Jacob Berab1
- Jacob ben Jacob, ha-Kohen, -approximately 12701
- Jaghmini1
- Jayakr̥ṣṇa1
- John Fortescue1
- Josef ibn Tabul1
- Joseph ben Abraham Gikatilla1
- Joshua ibn Shuaib1