This edited collection brings together new research on public service interpreting and translation (PSIT) with a focus on ideology, ethics and policy development. The contributions provide fresh theoretical and empirical perspectives on the inconsistencies in language policy development observed in different geonational contexts and the often-reported tensions between prescribed approaches to ethics and practitioner experience. The discussions are set against the backdrop of developments in rights-based discourses on language support services and the professionalisation of the field, drawing attention to how stakeholders and interpreting practitioners navigate the realities of service in the context of shifting ideological landscapes. Particular innovations in the collection include theorisations about policy and practice that draw on political science, applied ethics and paradigms of trauma-informed care. The volume also presents research on settings that have received limited attention to date such as prison and charitable services for survivors of violence and trauma.