Assumptions regarding space and spatiality exist in all major theoretical traditions in international relations, from realism to constructivism, but the mutual constitution of space and social interaction in the study of world politics requires further conceptual development in its own right. This article suggests a preliminary research agenda for the study of space and social relations in IR by lending insight from Georg Simmel’s classical sociology of space. Simmel’s approach offers scholars of contemporary world politics an innovative conceptualization of the relations between physical and symbolic space (‘the physical-symbolic axis’) and between space and time (‘the spatio-temporal axis’); and a set of practical analytical tools to apply in IR research by defining the foundational qualities of space (exclusivity, divisibility, containment, positioning, and mobility) and suggesting a typology of distinct sociospatial formations: organized space, governed space, fixed space, and empty space. The article discusses the potential of Simmel’s nuanced relational approach to contribute to the contemporary study of world politics, and demonstrates its utility in two particular areas of research: the study of unbundled sovereignty and mobility in late modernity; and the study of empty spaces in IR.