Human-centred design has foregrounded usability and inclusion. Under planetary conditions of ecological crisis, however, it often leaves unresolved questions about who counts as “the human”, what counts as evidence, and how responsibility is assigned when harm is distributed unevenly across places, species, infrastructures, and populations. This manuscript uses “design beyond the human” as a descriptive orientation for reading across a critical interpretive review of 117 sources (primarily 2009–2026). Rather than proposing a new field, umbrella term, or unifying theory, the review shows how already-entangled more-than-human, justice-oriented, decolonial, Indigenous and pluriversal, environmental humanities, and sustainability debates redistribute design responsibility across briefs, methods, evidence, evaluation, and implementation. Its contribution is analytical and translational: it organises this literature into three interacting trajectories and develops a process-based framework, an operational workflow, and a worked example for examining how briefs, methods, evidence, evaluation, and implementation are reconfigured when design responsibility is extended across human and more-than-human relations. Across these trajectories, familiar objects of design research are recast as sites of negotiation, where responsibility extends across species, infrastructures, histories of extraction, and present and future risks.