The present research, utilizing the theoretical framework of middle powers and linking it to the concept of niche diplomacy, addresses the typology of the foreign policy of three regional middle powers in the Middle East: Iran, Saudi Arabia, and Turkey. In the theoretical literature of international relations, the concept of a middle power is considered a hybrid concept because it is based on both realism and liberalism. On the one hand, the realist approach, which emphasizes the "position" of actors in the power hierarchy of the international system, envisions a limited playing field for middle powers; on the other hand, the liberal approach, which emphasizes the "behavior" of actors and subsequently their diplomacy, provides a broader arena for middle powers. Accordingly, a middle power takes care not to scatter its capabilities, acting instead according to its specific capacity. In this context, a middle power is fundamentally committed to niche diplomacy. The main premise of the niche diplomacy concept is that middle powers should direct their diplomacy towards areas where they have specific (advantageous) niches. Therefore, niche diplomacy means imposing limits on foreign policy objectives in light of constraints in capabilities and opportunities.