This dissertation examines the theory and practice of development in South Vietnam’s Second Republic from the aftermath of the 1968 Tet Offensive to the signing of the Paris Peace Accords in 1973. Based on Vietnamese and American archival material, it explores the development approaches of both the South Vietnamese and United States governments. In particular, it examines the ways in which South Vietnamese elites and U.S. officials in Washington and Saigon responded to the various development paradigms on offer to postcolonial states between the 1950s and 1970s, namely modernization theory, community development, land reform, and an emerging neoliberal economics. In doing so the dissertation makes three primary arguments. In contrast to much of the literature on the final years of the American War in Vietnam, this dissertation argues that development remained a crucial component of the United States’ and South Vietnamese strategy after the Tet Offensive. It highlights both the continuities and changes in U.S. approaches to international development between the Johnson and Nixon years as well as arguing that debates about development strategies in Vietnam during this time presaged larger shifts in international development later in the 1970s. Secondly, it argues that South Vietnamese elites had a transnational development vision. They not only employed U.S. theories of development but also drew on the lessons offered by other states in the Global South, particularly Taiwan and South Korea. Finally, the dissertation argues that the South Vietnamese government employed development to earn domestic legitimacy and shore up its authoritarian governance. The dissertation makes three historiographical interventions. Firstly, it illuminates U.S. development practice in the Nixon era. Secondly, the dissertation shows that South Vietnamese officials shaped development outcomes, thus granting agency that is largely absent from accounts of this period. Finally, it demonstrates that historians must place South Vietnam within the larger framework of decolonization and East Asian anti-Communism.