In this paper, we discuss the unsettled politics of child and youth representation in international institutions. By introducing the collection of papers that constitute this Special Issue, we examine how international institutions empower children and youth through participation and recognition, but also how institutionalized rules, routines, and policy discourses constrain the realms of possibility available to them. While the contributions illustrate how the politics of age and generation underpin IR as subject matter, they also prompt us to think of child and youth representation as unsettled and multifarious. We identify three ‘troubles of representation’ that complicate the involvement of children and youth in global policymaking: (i) the problem of speaking for others; (ii) representative hierarchies and barriers; and (iii) young people’s liminal position in-between worlds. Finally, we discuss how young people’s in-betweenness offers a productive prism that invites us to revisit the politics of representation and identify avenues for future research.