Ecocide, as a new concept in the literature of international law, refers to the widespread, severe, and irreparable destruction of the environment, which is accompanied by the intent or gross negligence of its perpetrators. The spread of environmental crises on a global scale, from climate change and the destruction of biodiversity to deadly industrial pollution, has highlighted the need to rethink existing legal frameworks. In the meantime, environmental justice as a normative approach emphasizes the balance between human needs, intergenerational responsibility, and the protection of ecosystems and can provide a theoretical foundation for the criminalization of ecocide. The main question of the present study is what is the relationship between the criminalization of ecocide and environmental justice and what is its place in the framework of international crimes and its relationship to violations of international law? The aim of this study, relying on a qualitative research method based on a descriptive-analytical approach to examining existing legal frameworks, analyzes the legal dimensions and challenges arising from the identification of this crime and explains the legal consequences. In the following, the main focus is on providing practical and diplomatic solutions to prevent the repetition of this type of action at the level of the international system. The present study does not have a research hypothesis. The results of the study show that identifying ecocide as the “fifth international crime” is not only necessary to strengthen criminal protection of the environment, but also helps to promote environmental justice and ensure the rights of future generations. However, obstacles such as the resistance of governments and transnational corporations, the weakness of enforcement guarantees in international law, and the difficulty of proving the psychological elements of the crime are considered to be the main challenges to achieving this goal.