- Hanbalites1
- Ibn Saʻādah, Aḥmad ibn ʻAlī, active 13th century. Risālat al-ʻilm1
- Ibn Umayl, Muḥammad, active 10th century. Qaṣīdah al-Nūnīyah1
- Ibn Wahbān, ʻAbd al-Wahhāb ibn Aḥmad, -1366 or 1367. Qaʼid al-sharāʼid wa-naẓm al-fawāʼid1
- Ibn al-Muṭahhar al-Ḥillī, al-Ḥasan ibn Yūsuf, 1250-1325. Mabādiʼ al-wuṣūl ilá ʻilm al-uṣūl1
- Ibn al-Nafīs, ʻAlī ibn Abī al-Ḥazm, 1210 or 1211-1288. Mūjaz fī al-ṭibb1
- Illumination of books and manuscripts, Iranian1
- Imams (Shiites)1
- Inheritance and succession1
- Inheritance and succession (Islamic law)1
- Intellect--Religious aspects--Islam1
- Iran1
- Iran--Qazvīn1
- Iraq1
- Islam and politics1
- Islam--Customs and practices1
- Islam--Rituals1
- Islamic New Year1
- Islamic calendar1
- Islamic interpretations of Jesus Christ1