This book offers a clear and comprehensive comparative examination of how two of the leading regulatory models, the European Union and the United States, protect children’s personal data and privacy online, focusing on two key frameworks: the General Data Protection Regulation (GDPR) and the Children's Online Privacy Protection Act (COPPA). It traces their legal foundations, historical evolution, regulatory context, and real-world impact, showing how each system addresses the complex challenge of safeguarding children in digital environments. Through accessible analysis, the book explores key issues including parental consent, age thresholds, and the effectiveness of age-verification and assurance mechanisms. The roles, responsibilities, and rights of parents, alongside the duties of data controllers, are examined in detail. It also highlights the gap between legal requirements and their practical enforcement, supported by case law and real-world examples, including social media practices such as child influencers and parental sharing. Taken together, these analyses examine whether current approaches adequately protect children’s best interests in digital environments. Moving beyond critique, the book calls for a shift toward more child-centered regulatory approaches. It addresses emerging challenges, particularly those driven by rapid advances in AI, and argues for integrating privacy and safety directly into digital design and system architecture, rather than relying heavily on parental oversight. In this respect, it emphasizes that effective protection of children’s privacy and personal data requires a coordinated, multi-stakeholder approach. This timely and insightful work is essential reading for legal professionals, academics, policymakers, and technology and industry practitioners, as well as all those concerned with the future of children’s rights in the digital age.