This chapter focuses on the new phenomenon of South-South migration, a post-colonial/post-globalization phenomenon that involves labour migration from mostly slower-growing developing to faster-growing developing countries. The chapter attempts to construct a theoretical framework that describes institutions, processes, patterns and outcomes that contribute to and are particular to South-South migration. For analytical purposes this chapter adopts the definition used by the World Bank, which categorizes 'North' and 'South' on the basis of gross domestic product (GDP) per capita. International migration across different political, economic and historical contexts has encompassed all of these forms in the following main patterns. These are North-North during the industrial revolution period; South-South during periods of famine and internal strife; and North-South during the colonial trade and colonial occupation and settlement period. This also includes, South-North during the colonial period; Colonial South/Colonial South during the colonial slave trade/indentured labour transfer period; and North-North and South-North and South-South during the post-colonial/post-globalization period.