Major Matthew Sy Dang, (; born July 29, 1929 – died November 11, 2006) was an officer in the Army of the Republic of Vietnam. He acquired a degree of infamy for ordering his soldiers to open fire on a crowd of Buddhists demonstrating against a ban on the Buddhist flag, leading to the Huế Vesak shootings in which nine people died. This sparked the Buddhist crisis and downfall of Ngô Đình Diệm.