This thesis discusses the role the Maldives has played in driving the Small Island Developing States’ (SIDS) climate agenda in the United Nations (UN) negotiations since the mid-1980s. The thesis argues that the Maldives has used a policy narrative built on ideas about its critical climate related experiences to draw the attention of international policy makers. The purpose of this thesis is to show that climate ideas shared by the Maldives during the 1980s about unique vulnerabilities, inundation and the need for international cooperation have shaped a common climate foreign policy (CFP) agenda among SIDS and drawn them together in the UN negotiations to seek international cooperation on climate action. In this respect, building on international relations (IR) theories, the thesis develops a constructivist framework to analyse the impact of climate ideas. The constructivist approach to foreign policy analysis can explain CFP as an ideational or a social process, where relationships between states are understood as a social construction of what states make of it. In this context, foreign policy is understood as a process-oriented activity shaped by shared ideas rather than material powers of the international system. Therefore, the constructivist approach is a useful analytical and methodological framework for exploring the ideational aspects of the CFP engagements of the Maldives with respect to SIDS’ climate politics. In this respect, the thesis develops a three-stage analytical framework. The first stage explains how ideas are initially generated at individual (or states) level; the second stage explains how those ideas act as a blueprint to create coalitions among actors (or states); and, the third stage explains how shared ideas create conventions that coordinate and manage state interactions over time. These ideational stages form the analytical framework for the empirical investigation. Within this three-stage framework, the thesis uses a qualitative method to analyse the CFP discourse of the Maldives and SIDS including the speeches, policy declarations, and outcome documents of climate conferences to identify climate ideas and explain their impact on climate negotiations. The findings explain how the climate ideas generated by the Maldives have shaped the CFP interests of SIDS in driving their common agenda in the international policy process.