The process of decision making about geopolitical interactions either has a public source and receives its legitimacy and legality from people and public arena or decisions are made and strategies are chosen by official institutions and political elites beyond the volition of public arena. Based on this fact, the current article tries to answer this question that what is the source of legitimacy of Iran's geopolitical interactions while it explains legal aspects of these interactions. Findings of this article indicate that geopolitical strategies of Islamic republic of Iran are based on laws ratified by parliament members of Iran's parliament and other lawmaking institutions. Therefore, these laws have public legitimacy. Thus Iran's geopolitical interactions have public legitimacy.