IntroductionUnpaid community volunteers are a vital public health resource in times of crisis. In response to the COVID-19 pandemic, community volunteers were mobilized to support mass vaccination efforts in many countries. To have this group’s continued engagement, it is essential to understand the community volunteer experience, including the opportunities and challenges they encounter and how these contribute to their role satisfaction. This qualitative study investigated the factors contributing to community volunteers’ role satisfaction at COVID-19 mass vaccination clinics in the Region of Waterloo, Canada.MethodsQualitative data were analyzed from 20 volunteers (aged 48–79 years) who had worked at one of four COVID-19 vaccination clinics in the Region of Waterloo, Canada. Data were analyzed thematically using an inductive coding process followed by an iterative process of grouping and identifying linkages and relationships within the themes.ResultsFour interrelated themes were developed from the inductive analysis process. The theme of community volunteers feeling valued or disesteemed in their role depends on the interaction between the three themes of role description, role preparation, and clinic context.ConclusionsFor volunteers in crises such as the COVID-19 pandemic, volunteer role satisfaction depends on how their contributions are valued, the clarity of their role descriptions, volunteer-specific training, and the sentiments of volunteers and staff within the clinic context. Greater role satisfaction can help with retention as volunteers become more resilient and adaptable to the complex dynamic circumstances of a crisis response. Activities such as training and materials development for role preparations should be explicitly planned and well-resourced, even in crisis/pandemic situations. Building clinic managers’ or supervisors’ skills in communication during crisis/pandemic situations and the skills for the creation of team cohesion are critical investment areas.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-023-15597-9.