Encyclopedias, Almanacs, Transcripts, and Maps
- Iconography: Confucian Iconography
- Iconography: Daoist Iconography
- Iconography: Egyptian Iconography
- Iconography: Greco-Roman Iconography
- Iconography: Hindu Iconography
- Iconography: Islamic Iconography
- Iconography: Mesoamerican Iconography
- Iconography: Mesopotamian Iconography
- Iconography: Native North American Iconography
- Iconography: Traditional African Iconography
- Icosteoidei (Ragfish)
- ideal gas law
- Igbo Religion
- Ignatius Loyola
- Ignatius of Antioch
- Ījī, ʿAḍud al-Dīn al-
- Ijmāʿ
- Ijtihād
- Ikhwān Al-Ṣafāʾ
- Ikkyū Sōjun