The purpose of this study was to examine the relationship between collective action, collective efficacy, self‐efficacy, and social support among US veterans who formally volunteered in their communities upon their return from military service. The participants were 323 post‐9/11/01‐era veterans who completed a national nonprofit administered civic service program. Results from the structural equation model indicate that appraisal social support is negatively, directly associated with collective action, while belonging social support is positively, directly associated with collective action. In addition, appraisal social support is positively, indirectly associated with collective action via self‐efficacy and collective efficacy. About 44% of the relationship between self‐efficacy and collective action is associated via collective efficacy. The model accounts 19.9% of the variance in self‐efficacy, 16.5% of the variance in collective efficacy, and 23.7% of the variance in collective action. The role of social support in the model provides additional evidence for the importance of strong social ties in facilitating collective action as veterans gather to volunteer in programs across the country. Results have implications for how national, nonprofit, and community volunteering programs may want to engage veterans and community members in collective action efforts.