Principles of human rights and social justice are fundamental to the social work profession. It has been well established that social workers can play a crucial role in redressing challenges faced by sexual minorities. Nevertheless, little is known about the roles of social workers in advocating social justice of sexual minorities in practice, particularly in South Africa. In this study, we therefore aimed to gain an understanding of social workers’ perceptions of their role to advocate social justice of sexual minorities. This article is extracted from a qualitative study with a sample of 16 social workers who were selected purposively. For the professional social workers to be eligible to participate in the study, they needed to be registered with the South African Council for Social Service Professions, provide services to sexual minorities, work as social workers for at least one year, and speak and communicate in English. The data presented in this article were analysed using thematic analysis. The findings of the study indicate that social workers perceive their role in advocating social justice of sexual minorities to include being an advocate, educator and broker. In addition, the findings reflect that social work professionals are confronted with personal and religious beliefs and the scope of practice as barriers to efficiently execute their roles when advocating social justice of sexual minorities. We conclude that social workers need to advocate social justice of sexual minorities at a policy level to move them from micro intervention practice to a macro practice intervention. Based on the findings of the study, we recommend that social work education and practicum cultivate advocacy skills for the social justice of sexual minorities.