Transparency is an important concept in International Relations. The possibility of realizing transparency in practice operates as a central analytical axis defining distinct positions on core theoretical problems within the field, from the security dilemma to the function of international institutions and beyond. As a political practice, the pursuit of transparent governance is a dominant feature of global politics, promoted by a wide range of actors across a vast range of issue areas, from nuclear proliferation, to internet governance, to the politics of foreign aid. Yet, despite its importance, precisely what transparency means or how the concept is understood is frequently ill-defined by academics and policymakers alike. As a result, the epistemological and ontological underpinnings of approaches to transparency in International Relations often sit in tension with their wider theoretical commitments. This article will examine the three primary understandings of transparency used in International Relations in order to unpack these commitments. It finds that while transparency is often explicitly conceptualized as a property of information, particularly within rationalist scholarship, this understanding rests upon an unarticulated set of sociological assumptions. This analysis suggests that conceptualizing ‘transparency as information’ without a wider sociology of knowledge production is highly problematic, potentially obscuring our ability to recognize transparent practices in global governance. Understanding transparency as dialogue, as a social practice rooted in shared cognitive capacities and epistemic frameworks, provides a firmer analytical ground from which to examine transparency in International Relations.