Định Bình Reservoir (Vietnamese: Hồ Định Bình) is a large artificial freshwater lake in Vĩnh Thạnh District, Bình Định Province, Vietnam. Work began creating the dam on Côn River in May 2003. It has a capacity of 226 million cubic metres. The lake and dam are expected to provide irrigation for some 12,545 hectares (over 48 square miles).