Indigenous Ecological Knowledge (IEK) represents the cumulative, place-based, and culturally embedded understanding of ecosystems developed by Indigenous peoples over generations. This knowledge encompasses practices, beliefs, and institutions that enhance ecosystem resilience, sustain biodiversity, and support adaptive resource governance. In the context of accelerating climate change, IEK is recognized as a vital component of climate adaptation strategies, particularly in Africa, where communities face heightened vulnerability due to environmental, social, and economic pressures. This entry explores IEK from theoretical, epistemological, and applied perspectives, emphasizing its relevance for socio-ecological resilience, hybrid governance, and ethical stewardship. Core debates around knowledge coproduction, epistemic justice, and the integration of IEK with Western science are critically analyzed. Case studies from the Democratic Republic of Congo, Niger, and Zambia illustrate how IEK informs forest management, soil restoration, water governance, and urban climate adaptation. The entry also outlines future directions, including digital integration, policy frameworks, and monitoring methodologies, highlighting the potential of IEK to transform global sustainability governance while respecting cultural integrity and social equity.