Francis Xavier Truong Buu Diep (Vietnamese: Cha Phanxicô Truong B?u Di?p or Cha Di?p, January 1, 1897 - March 12, 1946) was a Vietnamese Catholic priest who served the people of B?c Liêu Province.
Born in January 1, 1897 in An Giang Province, Father Diep was ordained in 1924 after completing his studies at Phnom Penh Major Seminary in Cambodia.
Upon his return to Vietnam, Father Diep taught at a local seminary and served as a pastor of Tac Say parish for 16 years.
He also founded many parishes in Cambodia and Vietnam.
He was arrested and killed by the Vi?t Minh on March 12, 1946 at the age of 49.
According to believers, his remains were lost until he appeared in a vision and disclosed the location and at least two posthumous miracles are attributed to him.