Since 1952, Türkiye’s Transatlantic identity has been largely shaped by its NATO membership and interactions with the Allies. During the Cold War, Türkiye aligned its national interests and security concerns with NATO, making its membership a central element of its identity. However, starting in the 2000s, Türkiye shifted toward a more independent foreign policy, influenced by its new activism and regional ambitions, particularly in the Middle East. This shift has caused tensions with NATO, especially considering Türkiye’s military interventions in Syria, its purchase of the S-400 missile defense system from Russia, and its reactions to the latest enlargement of NATO. This paper examines Türkiye’s evolving Transatlantic identity through the lens of ontological security, according to which states act in order to provide continuity in their identities (Türkiye’s Transatlantic identity) and to prevent any instabilities to feel ontologically secure, which then might create security dilemmas between the protective security cocoons (Türkiye’s NATO membership) and the crises with other actors (Türkiye’s clashes with/within NATO). In other words, this paper aims to understand how Türkiye’s Transatlantic identity is still valued, desired, and reconstructed, despite the security dilemmas of Türkiye’s contentions with/within the NATO Alliance, from the ontological security perspective.