South Korea is usually seen as a 'shrimp amongst whales', a minor player with limited agency in regional and global affairs. After colonization, the Korean War, national division and decades of military rule in the 20th century, however, South Korea today contributes to international peace and security with its peacekeeping troops and has successfully promoted its 'green growth' vision of sustainable development. The rising status of Korea begs the question about related changes in the South Korean identity or 'sense of self' in the world. In the respective International Relations and Korean Studies literatures this question has not yet been fully addressed beyond hopes for South Korea to be a future cornerstone of the liberal international order. Further, a wide variety of 'identity' conceptualizations has been leading to 'definitional anarchy' as well as 'confusion and analytical ambiguity' in the study of identity in general and South Korean international identity in particular. This thesis presents a theoretically rigorous and empirically rich approach for the inquiry into state identity through the utilization of conceptual tools from symbolic-interactionist role theory as a contribution to the research on state identity and foreign policy. By focusing on South Korean agency and domestic self-identification practices, the empirical analysis at hand is able to provide a comprehensive account of the various identity narratives and role conceptions at play in South Korea's global engagement in peacekeeping and climate diplomacy, complementing more systemic identity approaches such as the literature on norms and socialization. It argues that in the cases of peacekeeping and climate diplomacy South Korea's identity as an international actor has been dominated by practices of self-identification that locate the country at the brink of advanced countries, aspiring to lead the rest of the world on the basis of the Korean developmental experience, but with the overall objective to maintain national autonomy in a changing regional and global context. Finally, this study is a contribution to the Korean Studies literature on how South Korea confronts globalization on the level of identity and politics.