Any understanding of ecomedia requires thinking through both the “eco” and the “media,” which means contending with different conceptions of ecology (and environment) and multiple forms of media philosophy. In this chapter, I make a case for building on Félix Guattari’s formulation of “three ecologies” by providing a rigorous ontological theorization of these ecologies rooted in relational materialism. Specifically, I deploy the process-relational philosophy of A. N. Whitehead and the processual semiotics of C. S. Peirce to argue for an ontology of media that is also a form of ontology as media. That is, instead of thinking of media (and ecomedia) as specific kinds of things, the proposed ontology takes mediation to be central to the ongoing constitution of reality, with subjectivation, or the constitution of social and agential relations, and objectivation, or the constitution of material relations, as alternate sides of a dynamic continuum. Conceiving of three ecologies—social, material, and medial-perceptual—provides a holistic, dynamic, and ethically imbued approach to understanding how media are always already ecomedia, and how our work with them is a choice of better or worse forms of ecomediation.