The research deals with the issue of appeal and cassation before the Supreme Court in accordance with the Omani laws in the light of the provisions of Islamic law and international law. The purpose of the study is to present the provisions of the appeal and cassation against the juvenile delinquent in accordance with the Omani law as compared to the provisions of Islamic law and international law. The importance of the study lies in the fact that it reveals the appeal and cassation as one of the most important means of criminal protection that is established when the juvenile delinquent is held accountable until reaching a fair ruling that includes the maximum fairness and achieves the reform and rectification of the juvenile delinquent. The problem of the study is to explain the extent to which the two systems have been challenged in accordance with the Omani legislation to try a fair trial of juvenile delinquent who takes into account his physical weakness and cognitive shortcomings at an age where he needs more corrective treatment than punitive treatment and the extent to which these legal rules are in accordance with Islamic jurisprudence and international law. The study is based on several research approaches, the most important of which is the analytical approach, the inductive method and the comparative approach. The study requires a classification into three inquiries, the first dealt with the provisions of the appeal in accordance with the decision of the Omani legislator, the second dealt with the provisions of the cassation before the Supreme Court in Omani law, and the third dealt with the provisions of appeal and cassation before the Supreme Court in light of the provisions of Islamic jurisprudence and international law. The study concluded that the Omani law had the same general rules of procedure as he had decided in the appeal and cassation systems, which led to controversy in the treatment of some legal issues due to the specific treatment of juvenile delinquent, which necessitates interference with some legislative amendments as suggested by the researcher.