This paper explores the linkages between migration, international investment and trade from both economics and legal perspectives. The literature review reveals that the triangle of migration, investment and trade shows complex interdependences, both in terms of substitution and complementarities, though its components remain largely separated both institutionally and legally. The 2018 Global Compact for Safe, Orderly and Regular Migration addresses a number of trade- and investment-related issues. Recent treaty developments also encourage considering the triangle in a more integrated manner. The paper suggests undertaking such an effort under the emerging principle of Common Concern of Humankind, which provides a new foundation of international cooperation, obligations to do homework and enhance legal compliance in international relations. Given its importance and pressing needs, migration along other areas is destined to be developed as a Common Concern of Humankind. The emerging principle offers the potential to further develop the linkages between migration, trade and investment and shape the law and policies in a mutually supportive and more coherent manner. The paper sets out a number of preliminary ideas suggesting ways in which migration could be addressed in international trade regulation and trade policies, particularly agricultural trade, and in the field of investment protection.