Advocacy is a crucial vehicle for realising social work’s commitment to social justice. Yet, particularly in South Africa, little is known about social work research on advocacy. Therefore, this article uses a qualitative systematic review of published research on advocacy in South Africa’s social welfare sector in order to evaluate the contribution of social work research. It finds that there is scant research on social welfare advocacy in South Africa. Based on these findings, the article suggests areas for further social work research on advocacy in South Africa’s social welfare sector.