- Hermes, Trismegistus1
- Hermetism1
- Himalaya Mountains1
- Hindu law1
- Hindu philosophy1
- Houses (Astrology)1
- Hydrostatics1
- Ibn Ghāzī, Muḥammad ibn Aḥmad, 1437 or 1438-1513. Munyat al-ḥussāb1
- Ibn al-Hāʼim, Aḥmad ibn Muḥammad, -1412. Lumaʻ al-yasīrah fī ʻilm al-ḥisāb1
- Ibn al-Majdī, Aḥmad ibn Rajab, 1366-1447. Irshād al-ḥāʼir1
- Ibn al-Sarrāj, Aḥmad ibn Abī Bakr, active 14th century1
- Ibn al-ʻArabī, 1165-1240. Janāḥ al-ṭāʼir1
- Ibn al-ʻArabī, 1165-1240. Manẓūmat Kashf al-Rān1
- Indian philosophy1
- Inventions1
- Iran1
- Isfarāyīnī, Muḥammad ibn Muḥammad, -1285. Ḍawʼ al-Miṣbāḥ1
- Islam--Prayers and devotions1
- Islam--Rituals1
- Islamic astrology1