Phan Khắc Sửu (1893–1970) was Head of State of South Vietnam from 1964–65.
He was a trained agricultural engineer and was a founding member of the Cao Đài religion. He was a member of Emperor Bảo Đại’s political cabinet. Under President Ngô Đình Diệm’s rule, he was briefly jailed for mild dissidence but then released early when Diệm was assassinated. In the South Vietnamese presidential election, 1967, Phan finished third with 513,374 votes (10.8%).