Overtourism has given rise to conflict among various stakeholders. Accordingly, to control overtourism, the public sector has started to implement policies. Recently, Udo off Jeju Island in South Korea has begun experiencing overtourism; to prevent the situation from deteriorating, the public sector implemented a vehicle restriction policy. This study used a cost-benefit analysis framework to assess the social costs and benefits of the public policy to control overtourism in Udo. Through interviews and relevant data and documents, this study classified analysis items related to the policy that could be either a cost or benefit to different stakeholders. The social cost-benefit analysis showed that the net benefit increases, the longer the policy continues, thus ensuring it is adequate and feasible to implement the policy. An effective management public policy for the sustainability of the region’s tourism should always be promoted.