Obesity is a global problem for which sustainable solutions are yet to be realized. Community-based interventions have improved obesity-related behaviours and obesity in the short term. Few papers have explored how to make the interventions and their intended outcomes sustainable. The aim of this paper is to identify factors that contribute to the sustainability of community-based obesity prevention interventions and their intended outcomes. A systematic narrative synthesis review was conducted of published community-based obesity prevention interventions to identify factors contributing to intervention sustainability. Data extracted were included study authors' perspectives of intervention success and sustainability. Eighty-one papers met the inclusion criteria, and from these we identified ten factors that contribute to sustainability: resourcing, leadership, workforce development, community engagement, partnerships, policy, communications, adaptability, evaluation and governance. This review of community-based obesity prevention interventions gives rise to optimism that sustainable change is possible. We propose a framework to help practitioners build sustainability into their interventions and report on them so that others can also benefit.