The Iranshahri discourse has emerged as one of the most influential intellectual alternatives in contemporary debates on Iranian foreign policy. Distinct from competing discursive frameworks, it seeks to reconceptualize Iran's national interest by privileging the country's historical continuity, civilizational legacy, and state tradition as the principal sources of political identity. Against this background, this article examines how the Iranshahri discourse reconstructs the concept of national interest through its particular understanding of collective identity and explores the foreign policy implications of this reconstruction. The study adopts a constructivist theoretical perspective and employs an interpretive discourse-analytic approach to examine the identity narratives embedded in the political thought of the Iranshahri tradition, with particular reference to the writings of Seyyed Javad Tabatabai. Rather than treating national interest as an objective or fixed category, the analysis conceptualizes it as a socially constructed outcome of identity formation and discursive representation. The findings suggest that the Iranian Self is constituted around four interrelated identity foundations: the historical continuity of Iran, constitutionalism, the Persian language as a defining marker of collective identity, and a state-centered political tradition. This identity is discursively constructed through a dialectical relationship with two distinct categories of Others: the West as a transcendent Other and the Turkic and Arab worlds as constitutive Others. The analysis further demonstrates that the foreign policy vision articulated within the Iranshahri discourse rests upon three interconnected assumptions—strategic depth, strategic solitude, and the notion of Greater Cultural Iran. At the regional level, this framework prioritizes the consolidation of Iran's cultural and political influence while reinforcing processes of differentiation from the Turkic and Arab spheres. At the international level, it advocates a less ideological foreign policy by reducing the salience of Islamic identity and displaying a greater affinity with liberal democratic norms and closer strategic engagement with the West. The article concludes that, despite its emphasis on a secular and civilizational conception of Iranian identity, the Iranshahri discourse remains constrained by the structural dynamics of international politics. Consequently, its ability to provide a sustainable foundation for Iran's national interest ultimately depends on the extent to which these structural constraints can be accommodated within its foreign policy vision.