This introductory essay conceptually situates the dialogue between Actor-Network Theory (ANT) and Social Movement Studies that this special issue aims to foster. Rather than considering ANT as a theory in the classic sense, we define it as a theoretical sensibility open to permanently redrawing its own shape in response to the relational entanglements it studies. ANT and its sibling, assemblage theory, have allowed scholars to attend to the complex ecologies within which agents, both human and non-human, mobilise to effect change in overlapping social, ecological, economic and technological realms. In these studies, relations take precedence over substances, thereby forging a radically decentred, redistributed approach to mobilisation. As such, ANT offers a point of departure from dominant understandings of social movements that rely on modernist, dualist epistemologies; ANT studies have expanded the body politic through the incorporation of non-human actants, and redefined collective action as a form of association between heterogeneous entities. Ultimately, we argue that ANT is a useful tool in the task of constructing forms of attention and care that aspire to learn from and think with social movements, rather than explaining them away.