We conceptualize informal work in relational terms, examining informality through the relations and interactions between and among a set of actors: capitalists, the state, organizations of informal workers, traditional trade unions, individual informal workers. We consider the leading explanations of the persistent growth of informal employment around the world, suggest that three such explanations (survivalist, structuralist, and “disembedded”) are most compelling, and reframe them in terms of key actors and their relations. Finally, we take a closer act at the agency and strategies of each of those key actors. Throughout, we illustrate with examples from the articles in this special issue.