At the beginning of the 19th century, Ottoman-Iranian relations entered a new diplomatic phase shaped by Russia’s expansion in the Caucasus and Britain’s growing influence in the Persian Gulf. This shared perception of external threats led to the establishment of a more structured and representative diplomatic framework between the two empires. This study examines the embassy of Yâsincizâde Abdülvehhâb Efendi, who was appointed as Ottoman ambassador to Iran between 1810 and 1813, in the context of a shifting diplomatic mindset. Yâsincizâde’s mission is analyzed not merely as a temporary diplomatic engagement, but as a form of ideological, sectarian, and cultural representation by a figure from the ulema class. Based on archival sources, the study reveals that his diplomatic reports and observations provided critical input to the central administration, contributing to the development of more institutionalized and long-term strategies in Ottoman policy toward Iran. By focusing on the transitional character of his embassy, the paper reassesses the evolving role of religious scholars in Ottoman foreign relations, and situates this case between the classical sefaretnâme tradition and emerging modern diplomatic practices.