"‘Viability’ is a key term in debates about land reform in southern African and beyond, and is used in relation to both individual projects and programmes. ‘Viability’ connotes ‘successful’ and ‘sustainable’ - but what is meant by viability in relation to land reform, and how have particular conceptions of viability informed state policies and planning approaches? More broadly, how have different notions of viability influenced the politics of land in recent years? This paper interrogates this influential but under-examined notion, reflecting on debates about the viability of land reform – and in particular about the relevance of smallscale, farming-based livelihoods – in southern Africa and more broadly. This article describes the origins of a hegemonic, ‘large-scale commercial farm’ version of viability and its influence on policy debates on land redistribution in South Africa, Namibia and Zimbabwe. The discussion is located in the context of competing analytical paradigms for assessing land reform: neo-classical economics, new institutional economics, livelihoods approaches, welfarist perspectives, radical political economy and Marxism. Against this backdrop, we propose an approach to thinking about viability that draws on key insights from different frameworks, and we use these to suggest what a re-casting of the debate might imply for policy and practice in southern Africa today."