This article explores how the concept of agency in social theory changes when it is conceptualized as a relational rather than an individual phenomenon. It begins with a critique of the structure/agency debate, particularly of how this emerges in the critical realist approach to agency typified by Margaret Archer. It is argued that this approach, and the critical realist version of relational sociology that has grown from it, reify social relations as a third entity to which agents have a cognitive, reflexive relation, playing down the importance of interaction. This upholds the Western moral and political view of agents as autonomous, independent, and reflexive individuals. Instead, the article considers agency from a different theoretical tradition in relational sociology in which agents are always located in manifold social relations. From this, an understanding is created of agents as interactants, ones who are interdependent, vulnerable, intermittently reflexive, possessors of capacities that can only be practised in joint actions, and capable of sensitive responses to others and to the situations of interaction. Instead of agency resting on the reflexive monitoring of action or the reflexive deliberation on structurally defined choices, agency emerges from our emotional relatedness to others as social relations unfold across time and space.