In the age of technopolarity, where algorithmic influence and digital asymmetry increasingly define the global order, this chapter introduces cognitive diplomacy as an AI-augmented model of statecraft. It explores how states can integrate artificial intelligence with human judgment to enhance diplomatic presence, practice, and resilience. Rooted in international relations theory and cognitive science, cognitive diplomacy responds to a world in which perception, narrative, and epistemic control have become strategic resources. Through real-world examples from the United States, China, Estonia, Ukraine, and Türkiye, the chapter illustrates how AI tools are transforming diplomatic communication, negotiation, and decision-making. It argues that cognitive diplomacy enables states to project influence in contested information environments, build adaptive institutional capabilities, and defend strategic autonomy amid growing digital dependencies. The framework’s three pillars—cognitive presence, cognitive practice, and cognitive resilience—provide a conceptual and operational structure for sovereign engagement in AI-mediated global affairs. While offering enhanced agility and strategic foresight, cognitive diplomacy also presents normative challenges, including bias, transparency, and legitimacy. Addressing these concerns, the chapter frames cognitive diplomacy not only as a technological adaptation but as a political imperative for safeguarding autonomy in a cognitively contested international system. It is diplomacy for the digital mind—designed for agency, legitimacy, and resilience.