This chapter traces the origins, forms, structure, forms, stages, and classifications of Islamic education vis-à-vis the traditions of Qurʾānic, Islamic, and Ajami knowledge systems in Nigeria during the precolonial, colonial, and postcolonial periods. It shows that the Islamic knowledge system entails more than the study of Islamic sciences and deals with all activities of the intellectual development of humankind, including technology, culture, mysticism, history, dream interpretation, language, entertainment, and so on. It shows how organized and sufficient the system had been, demonstrating the breadth and depth of approaches to the past that Nigerians have engaged with. The chapter posits that there is persistence in this knowledge system’s relevance despite disruption by some factors including lack of funding, coordination, and supervision in the Nigerian education system. The chapter also provides policy recommendations to salvage and sustain the Islamic knowledge system in Nigeria.