The evolution of criminal justice approaches toward juvenile offenders in recent decades, particularly under the influence of the Convention on the Rights of the Child and other international instruments, has underscored the necessity for countries to review and revise their criminal justice policies. This study conducts a comparative analysis of the extent and manner in which these instruments have shaped the structures and processes of Iran’s juvenile justice system in dealing with juvenile delinquency. Employing a descriptive-analytical methodology and utilizing documentary sources, the research clarifies the theoretical foundations of criminal justice, the notions of juvenility and delinquency, and the importance of considering individual, social, and cultural factors in criminal policy-making. The study then examines the core principles of the Convention on the Rights of the Child—including prioritizing rehabilitation, differential proceedings, and the protection of the best interests of the child and adolescent—as well as the Beijing, Riyadh, and Havana Rules as supporting frameworks. The findings indicate that, although certain requirements of international instruments have been incorporated into Iran’s legal system, fundamental challenges remain—such as the divergence in the minimum age of criminal responsibility, the lack of fully differentiated proceedings, and the predominance of punitive approaches—which hinder full compliance with global standards. Ultimately, the study offers recommendations for the structural and procedural alignment of Iran’s juvenile justice system with international instruments, emphasizing the necessity of ongoing reform and the adoption of a justice-oriented approach.