As an activity, interpretation in international law is ubiquitous, involving all types of facts, processes, doctrines, values and theories. As a concept, however, international legal interpretation has played a much smaller role. Until recently, international lawyers largely associated interpretation with a limited set of objects (treaties), methods (those found in the 1969 Vienna Convention on the Law of Treaties) and functions (the exposition of meanings). In this short chapter, I problematize such traditional understandings of interpretation in international law. I explain how standard accounts oversimplify interpretation’s role in the treaty context; international law has moved beyond the Vienna Convention’s text to include larger questions about treaty interpretation’s scope, nature and purpose. At the same time, interpretation’s fixation on treaties understates its potential to reach additional objects, methods, and functions. The proliferation of international tribunals, institutions, and nontreaty instruments offer new objects for interpretation that require methodologies beyond the Vienna Convention, whether drawn from law or other disciplines. And, while the core of interpretation retains its expository function, the concept can (and does) serve other functions, be they inventive, relational or even existential. I conclude with a call for more attention to the work interpretation does for international law. As States and scholars continue to elaborate a deeper and broader understanding of this concept, it is poised to occupy an even more central place in our understanding of the international legal order and the discourse that sustains it.