Objective: The study explored how non-Indigenous psychologists enact clinical and cultural competence in their work with Aboriginal and Torres Strait Islander clients, with a particular focus on client assessment, diagnosis, and interventions. Method: Semi-structured individual interviews were conducted with 12 non-Indigenous psychologists from across Australia experienced in working with Aboriginal and Torres Strait Islander people in diverse geographic and organisational contexts. Results: Thematic analysis of the data revealed five primary themes associated with the engagement, assessment, diagnosis, intervention, and management of Aboriginal and Torres Strait Islander clients. Central to the findings was the need for adaptability and flexibility, a willingness to step outside psychology's traditional functions and formalities, the importance of adopting relationship-centred, trauma-informed, and client-specific approaches, the development of cultural competence as a journey rather than a destination, and the place for innovative and solutions-focused practice in building the knowledge and evidence base. Conclusion: This study demonstrates how non-Indigenous psychologists can adapt their practice to incorporate culturally sensitive approaches when working with Aboriginal and Torres Strait Islander clients.