BREAKING Pope Leo XIV Appoints Monsignor Peter Bui from Vietnam as New Auxiliary Bishop of Phoenix, Arizona, U.S.A.

Pope Leo XIV Appoints Monsignor Peter Bui as Auxiliary Bishop of Phoenix

Pope Leo XIV has appointed Reverend Monsignor Peter Dai Bui, as Auxiliary Bishop of Phoenix. Monsignor Bui is a priest of the Diocese of Phoenix and currently serves as the diocese’s Vicar for Clergy.

December 19, 2025
WASHINGTON – Pope Leo XIV has appointed Reverend Monsignor Peter Dai Bui, as Auxiliary Bishop of Phoenix. Monsignor Bui is a priest of the Diocese of Phoenix and currently serves as the diocese’s Vicar for Clergy. The appointment was publicized in Washington, D.C. on December 19, 2025, by Cardinal Christophe Pierre, apostolic nuncio to the United States.

The following biographical information for Bishop-elect Bui was drawn from preliminary materials provided to the U.S. Conference of Catholic Bishops:

Monsignor Bui was born January 11, 1970, in Phu Quoc Island, Vietnam. He studied at the Legion of Christ Minor Seminary and entered the Legion of Christ Novitiate in Cheshire, Connecticut in 1989, making his First Profession in 1991. Monsignor Bui attended the Pontifical Athenaeum in Rome, earning degrees in philosophy and theology as well as a licentiate in philosophy (2003). He was ordained to the priesthood on December 24, 2003, for the Legionaries of Christ (a religious order).

Bishop-elect Bui served as chaplain of a private Catholic school in Caracas, Venezuela, organizing mission trips to Amazonia and Medellin, Colombia (2003-2006). He was incardinated into the Diocese of Phoenix in October 2009. His pastoral assignments in the diocese have included: associate pastor of Our Lady of Guadalupe parish in Queen Creek (2007-2008); associate pastor at Christ the King parish in Mesa (2008-2010); pastor at Resurrection parish in Tempe (2010-2011); and pastor at Holy Spirit parish in Tempe (2017-2022). Bishop-elect Bui also served as an official on the Pontifical Council Cor Unum from 2011-2016. On December 16, 2014, he was named a Chaplain to His Holiness, with the title of Monsignor. Since 2022, Monsignor Bui has served as the Vicar for Clergy for the Diocese of Phoenix. He speaks English, Vietnamese, Spanish, Italian, and German.

USCCB Release