The conceptual history of 'economic development' is often told as a US-centered story. The United States, according to the standard account, turned to economic development as a tool in its struggle for global dominance during the Cold War. In line with recent research, this article demonstrates that the post-World War II boom in economic development had European origins as well, and that it originated as a joint response to the Cold War and to the unraveling of European empires. In particular, emphasis is placed on the little-studied contribution of a French Catholic activist who helped redefine economic development in the late 1950s and early 1960s. The Dominican Father Louis-Joseph Lebret stood at the head of an influential movement, which conceived of economic development as a way to save both France and Christianity in a moment of crisis for the French empire and for the Roman Catholic Church. In his writings, Lebret bestowed renewed legitimacy on the French 'civilizing mission.' He also revived elements of interwar Catholic thought to argue for the imperative of building a new moral-economic order that was neither communist nor capitalist. Far from a marginal historical actor, this theorist-practitioner was successful in his efforts, and gained followers for his vision of economic development in France, in Vatican City, at the United Nations, and in various former colonized countries.