This dissertation examines the emergence of a multicultural sensibility among American evangelical Protestants and their global peers in the late twentieth century. I trace this sensibility through the history of the Lausanne Movement, one of the largest evangelical missionary organizations of its kind, from the mid-1970s through the early 2000s. The Lausanne Movement brought together evangelical Christians from the Global North and South, and provided an unprecedented platform for evangelicals from the decolonizing world to confront their conservative North American co-religionists on roughly equal terms.Deeply influenced by the radical political currents of the global sixties, I argue that Global South evangelicals within the Lausanne Movement forced their peers to rethink their approach to mission work and develop new answers to charges of cultural imperialism. In so doing, these radical evangelicals prompted a revolution in evangelical understandings of religious identity—even if their political entreaties did not result in a widespread evangelical embrace of liberationist politics. I trace multicultural thought in the Lausanne Movement from its emergence in the 1970s, its molding by disparate groups within the Movement—including Global South radicals, evangelical missionaries to Muslims, technocratic North American mission theorists, and Messianic Jews—and its cementing in the global evangelical lexicon in the early twenty-first century.By placing U.S. evangelical Christianity in global context, I offer a new perspective on the history of American Christianity in the late twentieth century. In addition, I re-think the intellectual history of "multiculturalism" as a concept, offering a fresh interpretation of this putatively secular ideological project. Finally, I highlight the contributions of overlooked actors in the shaping of global evangelicalism, showing the unexpected ways that diverse perspectives on evangelicals' moral and religious mission continue to resonate today.