- Ibn al-Nafīs, ʻAlī ibn Abī al-Ḥazm, 1210 or 1211-1288. Mūjaz fī al-ṭibb1
- Ibn al-Nāẓim, Muḥammad ibn Muḥammad, d. 1287 or 8. Sharḥ al-Alfīyah1
- Ibn al-Sāʻātī, Aḥmad ibn ʻAlī, 1254-1294 or 1295. Badīʻ al-niẓām al-jāmiʻ bayna Kitāb al-Bazdawī wa-al-aḥkām1
- Ibn al-ʻImād al-Aqfahsī, Aḥmad, approximately 1349-1405. Ādāb mā yatakarraru fī al-yawm wa-al-laylah1
- Ibn ʻAqīl, ʻAbd Allāh ibn ʻAbd al-Raḥmān, 1294?-1367. Sharḥ al-Alfīyah1
- Illegible markings1
- Illumination of books and manuscripts, Dutch1
- Illumination of books and manuscripts, Renaissance1
- Immortality1
- Indexes1
- Indulgences1
- Indulgences (Canon law)1
- Inheritance and succession (Canon law)1
- Inheritance and succession (Roman law)1
- Initials (Abbreviations)1
- Innocent III, Pope, 1160 or 1161-12161
- Inquisition1
- Intellectual life1
- Interdict (Canon law)1
- International trade1