This dissertation investigates the history of the World Council of Indigenous Peoples (WCIP) and the broader movement of Indigenous internationalism. It argues that Indigenous internationalists were inspired by the process of decolonization, and used its logic to establish a new political identity. The foundation of the WCIP helped create a network of Indigenous peoples that expressed international solidarity between historically unconnected communities. The international efforts of Indigenous activists were encouraged both by personal experiences of international travel and post-secondary education, and by the general growth of international non-governmental organizations during the late twentieth century. The growing importance of international non-governmental organizations helped the WCIP secure funding from international developmental aid agencies, a factor which pushed the organization to increase its focus on apolitical economic development relative to the anti-colonial objectives which inspired its foundation. This dissertation examines how Indigenous international organizations became embroiled in the Cold War conflict in Latin America, and the difficulties this situation posed for both the WCIP and the International Indian Treaty Council. Finally, it examines how the prominence of the World Council faded, as major international bodies like the United Nations began to acknowledge the importance of Indigenous peoples, and as Indigenous organizations sought to participate directly in new international fora rather than contributing through the WCIP.