Phan Khắc Sửu (Vietnamese pronunciation: [faːn˧˧ xak̚˧˦ siw˧˩]; chữ Hán: 潘克丑 9 January 1893 – 24 May 1970) was a South Vietnamese engineer and politician who served as a minister in Bảo Đại's government of the State of Vietnam and as a civilian Chief of State of the Republic of Vietnam from 1964–65 during the rule of the various military juntas.

[2][3] He was born on 9 January 1893,[4][5] to a family of landowners in Mỹ Thuận village, An Trường canton, Cái Vồn district, Cần Thơ province, French Indochina.

Therefore, he was sentenced to eight years of hard labor by the colonial government of Indochina Governor General Jean Decoux and imprisoned on Côn Đảo.

He and Doctor Phạm Ngọc Thạch [vi] founded the Vietnam National Independence Party in Saigon, an anti-French political organization with Japanese support.

The election resulted in an overwhelming victory for the Diệm regime with many Pro-Diệm deputies winning seats in the National Assembly.

Sửu and fellow Deputy Phan Quang Đán were the only opposition candidates who won their respective contests.

On 26 April 1960, he and 17 dignitaries signed the proclamation, later known as the "Caravelle Manifesto," criticizing the government's mistakes and demanding that the President make reforms in policies.

On the night of 11 July 1963, he was sentenced to eight years in prison by a special military court in Saigon along with Phan Quang Đán, Vũ Hồng Khanh, and Bùi Lương.

However, Trần Văn Hương's government was quickly paralyzed by the opposition of many circles as well as the lack of cooperation of the Military Council.

Less than four months later, on 5 June 1965, Prime Minister Phan Huy Quát's civilian government was dissolved by the Military Council.

[13] Famous for his integrity, as chief of state, he only eats meals provided by the government, and his salary is transferred to the social welfare fund for the people.

In 1968, he, together with several dignitaries such as Nguyễn Thành Vinh and Trần Sinh Cát Bình founded the Vietnamese New People Movement.