The scholarly tradition of cosmopolitanism (illustrated by the old saying, “I am a citizen of the world”) offers important insights into the examination of agri‐food multinational corporations (MNCs) as powerful global actors. Acknowledging that agriculture is the business sector with the highest planetary environmental impact, in this paper, we advance existing discussions around cosmopolitanism and the normative implications of considering agri‐food MNCs as political actors. Relying on an integrative literature review, we propose a tripartite ethical framework that gives a new momentum to the ideals and tenets of cosmopolitanism. This novel lens offers an integrated, seamless ethical approach and revolves around three dimensions: culture, morality, and governance. The first dimension examines key agri‐food cultural and social‐ecological issues, the second acknowledges interdependence and causality as central to understanding MNCs’ ethical responsibilities, and the third outlines several governance parameters around legitimacy, planetary reach and efficiency. Hence, our integrative framework resituates the planetary geographical imagination of cosmopolitanism within the biophysical parameters outlined by the planetary boundaries concept, advancing key issues on private agri‐food environmental governance and planetary stewardship.