--- - |2 Abstract Developing theory for understanding social transformation is essential for environmental sustainability, yet mainstream accounts of collective action neglect the dynamics of daily life. Theories of practice have proved generative for the study of sustainable consumption but struggle to accommodate the roles of collective actors, strategic action and purposive collective projects in social change. In response, this paper develops a practice theoretical account of collective action pertinent to processes of large scale social change, with specific focus on transitions towards sustainability. We consider three ideal types of collective—bureaucratic organisations, groupings and latent networks—and, drawing on existing social theoretical resources that are ontologically compatible with a practice account, explore the kinds of practices and arrangements which compose them. Processes concerning strategy, bureaucracy, management, social worlds and collective identity are identified as important combinations of practices and arrangements. We suggest a key contribution of practice theory has been to identify a type of collective action we call dispersed collective activity, and we suggest how this type of activity may give rise to collectives. We conclude by suggesting further development for the realisation of the project's contribution to the analysis of sustainability transitions. - Journal for the Theory of Social Behaviour, Volume 48, Issue 3, Page 288-305, September 2018.