Ethnic diversity in any country requires policy-making in proportion to the foundations of the political system and the diversity situation in that country. Iran is also one of the countries with ethnic diversity. Justice in the Islamic Republic of Iran is a fundamental discourse and a legitimate factor that should be based on that policy. Therefore, justice in the policy of ethnic diversity is important and has implications as well. In this article, while selecting the approach and definition of justice as the practice of assigning the appropriate position for each object, the status and importance of justice in the policy of ethnic diversity in the Islamic Republic of Iran has been considered both theoretically and practically. In the next step, the implications of adopting a just approach to ethnic diversity policy in the Islamic Republic of Iran have been extracted. Studies and reviews show that the principal, purposeful, process, political and structural implications are derived from the adoption of a just approach to the policy of ethnic diversity.