This chapter examines the evolution and enduring relevance of Mustafa Kemal Atatürk’s guiding principle of “Peace at Home, Peace in the World” in shaping Turkish foreign policy from the founding of the Republic in 1923 to the present. Drawing on historical sources and a systematic analysis of Türkiye’s speeches at the United Nations General Assembly, the study explores how the concept of peace has been interpreted and applied across different periods of Turkish political history. It traces the transition from Atatürk’s early vision for peace, which was rooted in diplomacy, anti-revisionism, collective security, and economic justice, to contemporary understandings of peace that incorporate mediation, peacekeeping, and humanitarian engagement. The chapter argues that Atatürk’s approach anticipated many elements of modern peace theory, including multilateralism, conflict transformation, reconciliation, and the link between peace, justice, and development. Not only has Türkiye largely maintained a record of negative peace in the form of the absence of inter-state war, but Türkiye has incorporated broader definitions of peace into its diplomatic language at the official level and actively participated in global peacekeeping and mediation efforts. In short, even when Türkiye’s foreign policy approach evolved to address complex regional conflicts, the chapter demonstrates that it is still rooted in the foundational principle of “Peace at Home, Peace in the World.”