The Encyclopaedia of Islam (EI) is an encyclopaedia of the academic discipline of Islamic studies. It embraces articles on distinguished Muslims of every age and land, on tribes and dynasties, on the crafts and sciences, on political and religious institutions, on the geography, ethnography, flora and fauna of the various countries and on the history, topography and monuments of the major towns and cities. In its geographical and historical scope it encompasses the old Arabo-Islamic empire, the Islamic countries of Central Asia, the Indian sub-continent and Indonesia, the Ottoman Empire and all other Islamic countries.
It is an encyclopedia about the Islamic world, not a Muslim or an Islamic encyclopedia. Topics mostly deal with the pre-modern period, but some entries are contemporary.
The primary editor was Martijn Theodoor Houtsma (M. Th. Houtsma).