The domestic and foreign policies of the Attlee governments have shaped modern Britain. The Attlee governments’ legacy of domestic reform remains stubbornly embedded in the sociopolitical fabric of the nation, despite the relentless assault of Thatcherism, neoliberalism and austerity. The foreign policy choices of the Attlee government have also left indelible imprints on British relations with the outside world. The passing of time and the end of the Cold War have not diminished them, but they have obscured their parentage. In a world of upheaval, where Britain is still redefining its role in a post-Brexit world and where the essence of the ‘rules-based world order’ that the Attlee governments did so much to construct is under attack, reflecting on those influences becomes inevitable. This chapter looks at the activist policy in international affairs that Prime Minister Clement Attlee and Foreign Secretary Ernest Bevin adopted to promote British interests and aspirations in the immediate post-1945 period. It will attempt to highlight, albeit in a schematic fashion, to what degree their foreign policy choices are still shaping how the country interacts with the world.