Dr. Phan Huy Quát (Hà Tĩnh Province, 1908 or 1 July 1909 – 27 April 1979) served as acting Prime Minister of the State of Vietnam and also as Prime Minister of the Republic of Vietnam.
Quát was born in Hà Tĩnh Province. He attended the Lycée Pellerin, Huế, then studied medicine in Hanoi and qualified as a doctor before entering politics.
On 2 July 1949, Quát was appointed Minister of Education by Head of State Bảo Đại. On 22 January 1950, Prime Minister Nguyễn Phan Long appointed Quát Minister of Defense, at which position he had only served briefly before the Cabinet was re-organized and he returned to working for the Đại Việt Quốc dân đảng.
In June 1953, Prime Minister Nguyễn Văn Tâm appointed Quát Minister of Defense. Quát would be in this position until 1954 when Prince Bửu Lộc became Prime Minister who appointed Quát Special Minister in charge of the democratization process for Vietnam. Dr. Quát then served briefly as an interim Prime Minister until Bảo Đại appointed Ngô Đình Diệm to the position.
In April 1960, Quát signed the Caravelle Manifesto, a list of grievances and demands specifically critical of Diệm, and was promptly jailed by the GVN. After Diệm's assassination in October 1963, Quát was appointed Foreign Minister by Major General Nguyễn Khánh, one of the principal participants in the bloody coup. Though Quát frequently criticized Khánh's self-serving rule, he remained in Khánh's cabinet until November 1964, when Trần Văn Hương was installed as Prime Minister of General Khánh's freshly created High National Council (HNC).