This study examines criminal justice through the principle of the presumption of innocence as a cornerstone for achieving justice in modern legal systems, given its essential role in safeguarding individual rights and freedoms and preventing the abuse of penal authority. The research highlights the concept of innocence, its legal foundations, and its legal nature in light of various jurisprudential approaches, while clarifying the manifestations of justice that this principle embodies throughout the stages of criminal proceedings. It further emphasizes the impact of the presumption of innocence in establishing fair trial guarantees, particularly the burden of proof, the interpretation of doubt in favor of the accused, humane treatment, and the right to defense. The study concludes that respect for the presumption of innocence constitutes a genuine criterion for the fairness of the criminal justice system and the rule of law.