This Chapter in the Book, Participatory Approaches in Child and Family Social Work explores the significance of advocacy in promoting the rights and well-being of children in care. It begins with an introduction to the importance of advocacy and how this is linked to promoting children’s rights and well-being. It then provides an overview of the legal and policy framework for advocacy in child welfare services, including the role of independent advocacy. It explores the findings of empirical research conducted in a local authority in England on the effectiveness of advocacy for children in care. It further provides case examples to highlight the impact of advocacy on the experiences and outcomes of children and young people in care. It also explores ethical considerations and challenges in providing advocacy services for children in care. Finally, it discusses future directions for research and practice on advocacy for children in care and the need for a more comprehensive approach to advocacy that goes beyond individual casework. In summary, this chapter presents a comprehensive analysis of the importance of advocacy for children in care, with practical examples and empirical research to emphasise the significance of promoting the rights and well-being of looked-after children through effective advocacy support.