This thesis challenges the notion that thinkers associated with the French and British New Lefts were solely concerned with elaborating a “Western Marxism”. It does so by reconstructing the important role sociological and economic analyses of sub-Saharan Africa played in shaping the sociological and conceptual imagination of the French and British New Lefts. I show that sub- Saharan Africa was at the centre of comparative frameworks used to formulate several major ideas we today associate with the New Left. Chapter 1 charts how Eric Hobsbawm and Peter Worsley drew and expanded upon Max Gluckman’s interpretation of the Mau Mau uprising in colonial Kenya to sketch their respective accounts of how, and under what conditions, social movements ‘modernize’. Chapter 2 shows how the thought of South African émigré Marxists developed within British New Left milieus as a critique of liberal theories of industrialisation and modernisation. It then shows how thinkers associated with the French New Left, like Claude Meillassoux and Étienne Balibar, drew on the work of the South African Marxists and other Africanists to challenge the notion that contemporary capitalist societies were witnessing the disappearance of class. Chapter 3 shows how Stuart Hall’s influential interpretation of Thatcherism is indebted theoretically to the Africanist scholarship and development literature he was engaging with in the period. Chapter 4 pursues a genealogy of Orlando Patterson’s concept of “social death”, demonstrating that its origins lie in the work of French economic anthropologists of Africa. Chapter 5 argues that Arghiri Emmanuel’s theory of “Unequal Exchange” was deeply influenced by his experiences in the Belgian Congo. In the conclusion I consider reasons why New Left engagement with the sub-Saharan African context went into rapid decline from the late-1980s onwards. I show that the very thing that fascinated New Left thinkers about Africa in preceding decades - the failure of capitalist relations of production to definitively take root - began to feed into narratives about the continent being wiped off the face of the global economy.