Effective models for aligning public health and civil society at the local level have the potential to impact various global health issues, including tobacco. Georgia and Armenia Teams for Healthy Environments and Research (GATHER) is a collaboration between Armenia, Georgia and U.S. researchers involving a community randomized trial testing the impact of community coalitions to promote smoke-free policy adoption and compliance in various settings. Community Coalition Action Theory (CCAT) was used to guide and describe coalition formation, implementation and effectiveness. Mixed methods were used to evaluate 14 municipality-based coalitions in Georgia and Armenia, including semi-structured interviews (n = 42) with coalition leaders and active members, coalition member surveys at two timepoints (n = 85 and n = 83), and review of action plans and progress reports. Results indicated successful creation of 14 multi-sectoral coalitions, most commonly representing education, public health, health care, and municipal administration. Half of the coalitions created at least one smoke-free policy in specific settings (e.g., factories, parks), and all 14 promoted compliance with existing policies through no-smoking signage and stickers. The majority also conducted awareness events in school, health care, and community settings, in addition to educating the public about COVID and the dangers of tobacco use. Consistent with CCAT, coalition processes (e.g., communication) were associated with member engagement and collaborative synergy which, in turn, correlated with perceived community impact, skills gained by coalition members, and interest in sustainability. Findings suggest that community coalitions can be formed in varied sociopolitical contexts and facilitate locally-driven, multi-sectoral collaborations to promote health. Despite major contextual challenges (e.g., national legislation, global pandemic, war), coalitions were resilient, nimble and remained active. Additionally, CCAT propositions appear to be generalizable, suggesting that coalition-building guidance may be relevant for local public health in at least some global contexts.