This chapter examines the evolution and institutionalisation of bilateral relations between Brazil and the United States, highlighting how these ties have been crucial for the stability and continuity of cooperation in strategic areas. Throughout history, from the recognition of Brazil’s independence in 1824 to recent advances in cooperation on issues such as climate change and labour rights, the relationship has evolved from an asymmetric dependence to a more cooperative and balanced model. This study employs a combined methodology of institutional and longitudinal analysis to examine the mechanisms governing these relations, focusing on the professional role of diplomatic institutions and the active participation of civil society. The chapter is structured into six sections, addressing high-level diplomacy, economic and trade relations, energy and climate change cooperation, military cooperation, and social issues. Furthermore, it highlights how these relations have enabled Brazil to consolidate its strategic position within the global context and how it has adapted its cooperation with the United States to tackle contemporary challenges, such as energy transition and global climate governance. Despite the challenges posed by the multipolar international system, the institutionalised relations between the two countries remain a fundamental pillar of Brazil’s foreign policy, forming part of its global geopolitical strategy.