This article argues that the manner by which colonial societies achieved independence as sovereign states in the late 1940s and 1950s fundamentally shaped the parallel emergence of ideas and institutions of international governance, particularly at the newly created United Nations. Using Anglo-Indian relations as its primary focus, it argues that the internationalization of imperialism was particularly evident in two areas: postcolonial states’ negotiation of relations with their former colonial power within the UN system; and the influence of colonialism on international governance, particularly through the idea and practice of planning. The article assesses these developments through an analysis of British debates about United Nations membership for postcolonial states, India's role at the San Francisco Conference in 1945 where the United Nations was formed, India's campaign for a seat on the Security Council and its engagement with ECOSOC, the applicability of existing international conventions to postcolonial states, and the transfer of the ideal of planning from colonial to international governance.