African Indigenous Cultural Ontology (AICO) provides standards for some of the neglected aspects in the environmental conservation and management, particularly in today’s technological society. In the global level, this ontology has not been fully explored and appreciated. The claim of this chapter is that a fundamental feature of African contribution to environmental conservation lies in her rich ecological culture, which enables bio-systems to relate with their habitats. Under such ecological culture, indigenous Africans aim at living in a relationship of mutual responsibility with the natural environment. Any attempt to discredit the contribution of such indigenous cultural ontology to environmental management equally undermines the African involvement in the same process. This claim is supported by the holistic lifestyle of some selected Kenyan indigenous communities (Iteso, Kikuyu, Luyha, Kamba and Luo) that exhibit a similar regard of mutual relationship with the natural environment. The claim is discussed under the following objectives: to examine African Cultural Worldviews as a basis for African Environmental Ontology; to assess the contribution of African Indigenous Cultural Ontology to Environmental Conservation and Management; to give an account of African measures employed in regulating the use of the natural environment for its Conservation and Sustainability. The discussion is informed by the Cultural Sustainability Theory, which relates environmental conservation to enforcement of indigenous cultural practices. The discussion further employs the phenomenological method of cultural ontology, which provides insights into the place of indigenous culture in environmental conservation and management. The discussion advocates for a cultural ontological turn in regard to the natural environment; a turn which underlines the notable place of indigenous cultural metaphysics in environmental conservation.