Migration represents a major transformation of the lives of those involved and has been transformative of societies and economies globally. Yet models of sustainability transformations do not effectively incorporate the movement of populations. There is an apparent migration-sustainability paradox: migration plays a role as a driver of unsustainability as part of economic globalisation, yet simultaneously represents a transformative phenomenon and potential force for sustainable development. We propose criteria by which migration represents an opportunity for sustainable development: increasing aggregate well-being; reduced inequality leading to diverse social benefits; and reduced aggregate environmental burden. We detail the dimensions of the transformative potential of migration and develop a generic framework for migration-sustainability linkages based on environmental, social, and economic dimensions of sustainability, highlighting identity and social transformation dimensions of migration. Such a model overcomes the apparent paradox by explaining the role of societal mobility in achieving sustainable outcomes.