Rationale: Community mobilization approaches (CMAs) are increasingly becoming key components of health programming. However, CMAs have been ill defined and poorly evaluated, largely due to the lack of measurement tools to assess mobilization processes and impact. Objective: We developed the Community Mobilization Measure (CMM), composed of a set of scales to measure mobilization domains hypothesized to operate at the community-level. The six domains include: shared concerns, critical consciousness, leadership, collective action, social cohesion, and organizations and networks. We also included the domain of social control to explore synergies with the related construct of collective efficacy. Method: A survey instrument was developed and pilot tested, then revised and administered to 1181 young people, aged 18-35, in a community-based survey in rural South Africa. Item response modeling and exploratory factor analyses were conducted to assess model fit, dimensionality, reliability, and validity. Results: Results indicate the seven-dimensional model, with linked domains but no higher order construct, fit the data best. Internal consistency reliability of the factors was strong, with ¿ values ranging from 0.81 to 0.93. Six of seven scales were sufficiently correlated to represent linked concepts that comprise community mobilization; social control was less related to the other components. At the village level, CMM sub-scales were correlated with other metrics of village social capital and integrity, providing initial evidence of higher-level validity, however additional evaluation of the measure at the community-level is needed. Conclusion: This is the first effort to develop and validate a comprehensive measure for community mobilization. The CMM was designed as an evaluation tool for health programming and should facilitate a more nuanced understanding of mechanisms of change associated with CM, ultimately making mobilizing approaches more effective.