The international business landscape is increasingly shaped by grand challenges, such as climate change, global health, and digital inequality, that affect how organizations operate and contribute to society throughgh their scale, temporality, and interdependence. This dissertation examines how global organizing unfolds in distributed organizations under conditions of heightened grand challenge complexity. By drawing on a conceptual article, a qualitative single-case study of a United Nations agency, and a qualitative multi-case study of four multinational corporations, the findings show that global organizing is best understood as a fluid and evolving process through which organizations continuously redefine objectives, coordinate adaptively across heterogeneous contexts and sectors, and respond to shifting interdependencies among multiple organizational actors. Overall, the dissertation contributes to the international business literature and organization theory by advancing a more dynamic, relational, and process-oriented understanding of global organizing in increasingly complex global environments.