Bảo Đại (Vietnamese: [ɓa᷉ːw ɗâːjˀ], Hán tự: 保大, lit. "keeper of greatness", 22 October 1913 – 30 July 1997), born Nguyễn Phúc Vĩnh Thụy, was the 13th and final emperor of the Nguyễn dynasty, the last ruling family of Vietnam. From 1926 to 1945, he was emperor of Annam and de jure monarch of Tonkin, which were then protectorates in French Indochina, covering the present-day central and northern Vietnam. Bảo Đại ascended the throne in 1932.

The Japanese ousted the Vichy French administration in March 1945 and then ruled through Bảo Đại, who renamed his country "Vietnam". He abdicated in August 1945 when Japan surrendered. From 1949 to 1955, Bảo Đại was the chief of state of the non-communist State of Vietnam. Viewed as a puppet ruler, Bảo Đại was criticized for being too closely associated with France and spending much of his time outside Vietnam. He was eventually ousted in a referendum in 1955 by Prime Minister Ngô Đình Diệm, who was supported by the United States.