This chapter examines the role of music therapy in supporting assessments of the “best interests of the child,” as outlined in the United Nations Committee on the Rights of the Child General Comment No. 14 (2013). The document highlights seven key elements to be considered in decision-making regarding a child’s best interests: the child’s views, identity, family environment and relationships, care and protection, vulnerability, health, and education. Central to this framework is the necessity of interdisciplinary collaboration to balance these factors effectively. The chapter emphasizes music therapy’s unique contributions in interdisciplinary settings. By fostering emotional expression, strengthening identity, and promoting a safe and supportive environment, music therapy aligns with the best interest principle. Furthermore, the integration of music therapy into collaborative practices with professionals, agencies, families, and stakeholders ensures a holistic approach to addressing children’s individual needs and circumstances. The chapter underscore music therapy as an essential component in interdisciplinary efforts to uphold children’s rights and well-being, offering practical strategies for embedding the best interest principle in therapeutic and care frameworks.