Few studies have examined the agroecological transition in viticulture, which involves transformation processes, especially at the territorial scale where collective action plays a key role in the dissemination of transition strategies. Collective action in the agroecological transition must be studied in order to encourage and accelerate changes in practices. In this study, collective action is analyzed to understand how governance structures influence the development of collective agroecological transition strategies. Elinor Ostrom’s Institutional Analysis and Development and Social–Ecological Systems analysis frameworks were applied to the Anjou-Saumur wine area in the Loire Valley, where nearly 80% of wine production is under protected designations of origin. Data were collected through seven semi-structured interviews, which were analyzed qualitatively in order to identify the main actors and collective strategies in the agroecological transition. The study showed that the polycentric structure of governance in the protected designations of the origin system enables institutional actors to collectively coordinate their actions. Moreover, collective action is structured in three focal action situations that overlap at the institutional level due to two key actors in the agroecological transition, but also due to tacit rules of the organizational structure for some actors. Action situations dynamically interact with each other across time and geographical scales, helping the agroecological transition process forward by combining top-down and bottom-up strategies. This study provides a novel way of applying the IAD/SES framework as well as a new look at collective action for the agroecological transition at the institutional scale in French viticultural systems under protected designations of origin. This paves the way for interdisciplinary research for the agroecological transition, and might help to select the best strategies to encourage changes of viticultural practices.