This chapter outlines the theoretical foundations that inform child protection research and practice. It examines selected theories and perspectives relevant to individuals seeking to build careers in child protection, as well as social service practitioners currently working in the field. The chapter clarifies the concept of child protection, explains the rationale for prioritizing children’s protection, and discusses key theoretical approaches that can be applied to support research and professional practice in child protection. Vulnerability is presented as a central driver of child protection concerns and is discussed in relation to diverse childcare settings and subsystems within the systems theoretical framework. In addition, the chapter highlights strengths within children and their environments that foster resilience, recovery, and positive developmental outcomes. Finally, it illustrates how these theories can be translated into practice through policy development and program implementation to strengthen child protection.