The European Union (EU) has been long committed to multilateral action on the global stage. As a key actor within the United Nations Security Council (UNSC), this research dives into the EU's multilateral initiatives and its efforts to legitimise its presence alongside the United Nations, analysed through various theoretical frameworks. The study further explores the EU's evolution as a multilateral advocate and the mechanisms it has implemented to secure a recognised position on the global stage via the UNSC. Addressing the implications of contemporary UNSC reforms based on the application of theoretical frameworks, the research elucidates the motivations and advantages of the EU's active participation in the UNSC, while also highlighting the internal coordination and decision-making processes and challenges within the EU. Looking ahead, the EU is expected to maintain robust collaboration with the UNSC and other international organisations, despite challenges posed by France being the sole permanent EU representative. The EU's commitment to multilateralism, effective diplomacy, and its common foreign and security policy objectives are expected to guide its ongoing engagement.