Collective action has been studied by social psychologists for over a century. Social network sites such as Facebook have further extended the ability of individuals to instigate social, political and organizational change, and provide a new context in which to study collective action. Drawing on social identity theory (SIT), self-categorization theory (SCT) and uses and gratifications theory (UGT), this study explores the role of individuals’ group identification, social identity gratifications (SIG) and Facebook group use intensity on their willingness to participate in collective actions instigated through a Facebook group. Members of a Facebook group representing a cause against management completed an online survey (N = 406). Factor analyses reveal that motivations based on psychological affiliation with the group explained the most variance for Facebook group use. Moreover, compared to Facebook group use intensity, SIG were the stronger mediator between group identification and willingness to participate in collective action. The study demonstrates the utility of blending concepts from SIT, SCT and UGT to explore how socially motivated uses of the media can predict collective actions.