In the millennium after 300 BC, the western Indian Ocean emerged as a main hub of Old World exchange. Study of this commerce long depended on separate regional archaeologies and a handful of literary sources with Western/Roman bias. A recent surge in scholarly interest has led to a vast increase in data that has fostered a more balanced understanding of the commercial, human, and material aspects of ancient Indian Ocean trade. This review summarizes recent research on the topic and assesses its significance to wider scholarly debates on scale, organization, connectivity, agency, and social cohesion in ancient trade and exchange.