This chapter explores “indigenous” and “local” knowledge of “Pygmy” and “Bantu” peoples, respectively, and its relation to scientific understandings of Congo Basin ecology from historical and contemporary perspectives. Both peoples are heirs to extensive traditions of ecological knowledge. In the precolonial era, Indigenous knowledge was highly valued in regional societies, providing Pygmies with key roles to play in wider social systems. However, colonial policies had significant negative impacts on traditional knowledge, especially among Bantu communities. In the postcolonial era, more substantial challenges have occurred, undermining both traditional knowledge and the access of forest-dependent communities to their lands. Traditional knowledge has contributed to modern understandings of Congo Basin ecology since the colonial era, yet often without formal acknowledgment. Whereas scientists have tended to take an “extractive” approach to traditional knowledge, the chapter argues for the development of a more equal and “co-creative” approach to the sharing of knowledge. Acknowledging the complementarity between scientific and traditional knowledge, the chapter recommends that scientists communicate across disciplinary lines to develop methodologies to collect, assemble, and store Indigenous and local knowledge as a matter of urgency, before key forms of oral knowledge are lost. Bringing Indigenous and local peoples into the mainstream scientific research agenda should become a priority, for both regional policies and specific initiatives. By examining various cases of traditional knowledge, the chapter illustrates how important these forms of knowledge are, not only for furthering understanding of Congo Basin ecology but also for solving some vexing questions faced by local peoples across countries.