This chapter examines the interplay between migration routes and economic structures in Southeast Asia and provides an in-depth analysis of the ways in which labour mobility is influenced by regional economic dynamics. Through the lens of key migration theories, including neoclassical economics, dual labour market theory and world systems theory, the chapter examines the motivations, mechanisms and impacts of migration within and across national borders. Specific migration corridors such as Malaysia–Indonesia and Thailand–Myanmar illustrate how wage differentials, labour demand and regional politics influence the movement of people. The role of remittances in supporting the economies of sending countries such as the Philippines and Cambodia emphasises the profound economic impact of migration. By linking theoretical frameworks with empirical evidence, this chapter highlights the centrality of economic imperatives in shaping the Southeast Asian migration landscape, while also addressing policy challenges related to labour rights, integration and regional cooperation.