Peter Dai Bui
Peter Đại Bùi is a Vietnamese-born American Catholic priest who was appointed an auxiliary bishop for the Diocese of Phoenix in 2025.
Biography
Early life
Bui was born on January 11, 1970, in Phú Quốc, in what was then South Vietnam. His father was a fisherman, and he grew up as one of 12 children. When Bui was 6 years old, he and his family were among the boat people who fled Vietnam after the Vietnam War. 49 relatives and neighbors, including Bui's family, fled in his father's fishing boat and were at sea for three days. While at sea, pirates demanded their valuables. Eventually, the whole group arrived in Bangkok and received assistance. Later, Bui and his family settled in New Orleans, where some of his family still lives.Deciding to enter the priesthood, Bui entered the Legion of Christ's novitiate in 1989. During that time, he studied at the minor seminary in Cheshire, Connecticut and made his first profession of vows in 1991. He studied at Pontifical Athenaeum Regina Apostolorum in Rome, completing seminary studies in philosophy and theology. He also earned a licentiate in philosophy.
Priesthood
Bui was ordained a priest for the Legion of Christ on December 24, 2003. While a Legion of Christ priest, he served as the chaplain of a Catholic high school school in Caracas, Venezuela. He also organized international mission trips to Amazonia and Medellin, Colombia.In 2007, Bui was appointed to a parish in the Diocese of Phoenix. He ultimately left the Legion of Christ and was incardinated a priest of Phoenix in 2009. He served at various parishes in Phoenix from 2007 to 2011 and again from 2017 to 2022.
Bui served at the Vatican on the Pontifical Council Cor Unum for five years from 2011 to 2016. He compared his administrative position with service in the missions saying, "You can make of your desk an altar, to make an offering to the Lord". Due to his service at Cor Unum and the recommendation of Cardinal Robert Sarah, Bui was named a Chaplain to His Holiness by Pope Francis on December 16 2014, receiving the title Monsignor. While serving in Rome, Bui helped arrange a 2015 meeting between Pope Francis and the Harlem Globetrotters.
Following his return from Rome, Bui was appointed Theological Consultant to the Bishops of Phoenix in 2017. Also in 2017, he coordinated a 54-day novena and diocesan consecration to the Immaculate Heart of Mary. This devotion called for penance and prayer in the face of war and the issues of pornography and abortion which Bui called "attacks on the family." Since 2022, he has served as Vicar for Clergy for the Phoenix diocese.
On November 15 2022, Bui led a prayer vigil at St. Mary's Basilica to abolish the death penalty in Arizona. This service took place the evening before Murray Hooper's execution.
Bui commented on Pope Leo XIV's election, anticipating the new pope's similarity to Francis because both were bishops in South America.
Auxiliary Bishop of Phoenix
On December 19, 2025, Pope Leo XIV appointed Bui as auxiliary bishop of Phoenix and titular bishop of Ausafa. He is only the second auxiliary in Phoenix's history, following Bishop Eduardo Nevares. He will continue to serve as Vicar for Clergy while auxiliary bishop. Bui's episcopal consecration is scheduled for February 17, 2026 at Saint Thomas Aquinas Parish in Avondale, Arizona. The Mass will be celebrated by Bishop John Dolan, assisted by Auxiliary Bishop Nevares, and Bishop-emeritus Thomas Olmsted.Personal life
Bui is fluent in many languages, including Spanish, German, Italian, English and Vietnamese.In 2022, Bui was invested as a Knight of the Holy Sepulchre.