Information systems (IS) play an important role in helping organisations attain environmental sustainability targets, and how to use IS for sustainability transformation is attracting research attention. However, extant studies have mainly focused on such transformation of business enterprises, overlooking it of communities. Our study intends to fill this gap by conducting an in-depth case study at Feldheim, a small village in Germany that has successfully built a renewable energy system using IS and achieved energy self-sufficiency. Guided by the belief-action-outcome (BAO) framework, our study unveiled a process model of antecedents, belief and action formation, and outcomes specific to community-based sustainability transformation. The model also reveals three roles that IS assume in such transformation: participation objects, connectivity enablement, and fluctuation mitigation. Our study contributes to the literature on IS-enabled sustainability transformation by extending it from the business enterprise context to the community context. It also provides communities with guidelines for conducting IS-enabled sustainability transformation.