This paper focuses on the regenerative capacity of Indigenous languages to heal humanity's widespread disassociation from our earth. Decolonization is positioned as the collective work of reindigenization as this pertains both to Indigenous peoples and those who are no longer indigenous to place. In doing so, the paper elucidates the potential contribution of the Westernized field of ecopsychology, with its focus on the interrelationships between well-being, human culture, and environment. In particular, it focuses on elements of the new science, relational psychology, and poststructuralism to elucidate the ways in which Indigenous languages might enliven, shape, and consolidate human subjectivities and agency for sustainable futures. Drawing on Te Ao M aori (the M aori LifeWorld) and other Indigenous realities, it shifts the debate from Indigenous languages as a human right specific to Indigenous peoples, to Indigenous languages as an ecological imperative for humanity.